# Binäre

Subtracting a "1" digit from a "0" digit produces the digit "1", while 1 will have to be subtracted from the next column.

This is known as borrowing. The principle is the same as for carrying. Subtracting a positive number is equivalent to adding a negative number of equal absolute value.

Such representations eliminate the need for a separate "subtract" operation. Multiplication in binary is similar to its decimal counterpart.

Two numbers A and B can be multiplied by partial products: The sum of all these partial products gives the final result. Since there are only two digits in binary, there are only two possible outcomes of each partial multiplication:.

Binary numbers can also be multiplied with bits after a binary point:. Long division in binary is again similar to its decimal counterpart.

In the example below, the divisor is 2 , or 5 decimal, while the dividend is 2 , or 27 decimal. The procedure is the same as that of decimal long division ; here, the divisor 2 goes into the first three digits 2 of the dividend one time, so a "1" is written on the top line.

This result is multiplied by the divisor, and subtracted from the first three digits of the dividend; the next digit a "1" is included to obtain a new three-digit sequence:.

The procedure is then repeated with the new sequence, continuing until the digits in the dividend have been exhausted:. Thus, the quotient of 2 divided by 2 is 2 , as shown on the top line, while the remainder, shown on the bottom line, is 10 2.

In decimal, 27 divided by 5 is 5, with a remainder of 2. The process of taking a binary square root digit by digit is the same as for a decimal square root, and is explained here.

Though not directly related to the numerical interpretation of binary symbols, sequences of bits may be manipulated using Boolean logical operators.

When a string of binary symbols is manipulated in this way, it is called a bitwise operation ; the logical operators AND , OR , and XOR may be performed on corresponding bits in two binary numerals provided as input.

The logical NOT operation may be performed on individual bits in a single binary numeral provided as input. Sometimes, such operations may be used as arithmetic short-cuts, and may have other computational benefits as well.

For example, an arithmetic shift left of a binary number is the equivalent of multiplication by a positive, integral power of 2. To convert from a base integer to its base-2 binary equivalent, the number is divided by two.

The remainder is the least-significant bit. The quotient is again divided by two; its remainder becomes the next least significant bit.

This process repeats until a quotient of one is reached. The sequence of remainders including the final quotient of one forms the binary value, as each remainder must be either zero or one when dividing by two.

For example, 10 is expressed as 2. Conversion from base-2 to base simply inverts the preceding algorithm. The bits of the binary number are used one by one, starting with the most significant leftmost bit.

Beginning with the value 0, the prior value is doubled, and the next bit is then added to produce the next value. This can be organized in a multi-column table.

For example, to convert 2 to decimal:. The result is Note that the first Prior Value of 0 is simply an initial decimal value. This method is an application of the Horner scheme.

The fractional parts of a number are converted with similar methods. They are again based on the equivalence of shifting with doubling or halving.

In a fractional binary number such as 0. Double that number is at least 1. This suggests the algorithm: Repeatedly double the number to be converted, record if the result is at least 1, and then throw away the integer part.

Thus the repeating decimal fraction 0. This is also a repeating binary fraction 0. It may come as a surprise that terminating decimal fractions can have repeating expansions in binary.

It is for this reason that many are surprised to discover that 0. The final conversion is from binary to decimal fractions. The only difficulty arises with repeating fractions, but otherwise the method is to shift the fraction to an integer, convert it as above, and then divide by the appropriate power of two in the decimal base.

For very large numbers, these simple methods are inefficient because they perform a large number of multiplications or divisions where one operand is very large.

A simple divide-and-conquer algorithm is more effective asymptotically: Given a decimal number, it can be split into two pieces of about the same size, each of which is converted to binary, whereupon the first converted piece is multiplied by 10 k and added to the second converted piece, where k is the number of decimal digits in the second, least-significant piece before conversion.

Binary may be converted to and from hexadecimal more easily. This is because the radix of the hexadecimal system 16 is a power of the radix of the binary system 2.

To convert a hexadecimal number into its binary equivalent, simply substitute the corresponding binary digits:. To convert a binary number into its hexadecimal equivalent, divide it into groups of four bits.

To convert a hexadecimal number into its decimal equivalent, multiply the decimal equivalent of each hexadecimal digit by the corresponding power of 16 and add the resulting values:.

Binary is also easily converted to the octal numeral system, since octal uses a radix of 8, which is a power of two namely, 2 3 , so it takes exactly three binary digits to represent an octal digit.

The correspondence between octal and binary numerals is the same as for the first eight digits of hexadecimal in the table above. Binary is equivalent to the octal digit 0, binary is equivalent to octal 7, and so forth.

Converting from octal to binary proceeds in the same fashion as it does for hexadecimal:. Non-integers can be represented by using negative powers, which are set off from the other digits by means of a radix point called a decimal point in the decimal system.

For example, the binary number Other rational numbers have binary representation, but instead of terminating, they recur , with a finite sequence of digits repeating indefinitely.

The phenomenon that the binary representation of any rational is either terminating or recurring also occurs in other radix-based numeral systems.

See, for instance, the explanation in decimal. Another similarity is the existence of alternative representations for any terminating representation, relying on the fact that 0.

Conversion of 10 to binary notation results in Mathematics portal Information technology portal. The First 50, Years , Prometheus Books, pp.

Leibnizens Novissima Sinica von Internationales Symposium, Berlin 4. The mathematics of harmony: Proceedings of the National Academy of Sciences.

American Journal of Physics. Mitteilungen der deutschen Mathematiker-Vereinigung in German. Gerhardt, Berlin , vol. What Kind of Rationalist?: What Kind of Rationalist?

Leibniz, Mysticism and Religion. A symbolic analysis of relay and switching circuits. Massachusetts Institute of Technology. Archived from the original on 9 July Retrieved 5 July Computer History Association of California.

PC- und Mikrocomputertechnik, Rechnernetze in German. Retrieved 31 August Retrieved from " https: Binary arithmetic Computer arithmetic Elementary arithmetic Positional numeral systems Gottfried Leibniz.

The worst case may also be reached when the target element is not in the array. In the best case, where the target value is the middle element of the array, its position is returned after one iteration.

In terms of iterations, no search algorithm that works only by comparing elements can exhibit better average and worst-case performance than binary search.

The comparison tree representing binary search has the fewest levels possible as every level above the lowest level of the tree is filled completely.

This is the case for other search algorithms based on comparisons, as while they may work faster on some target values, the average performance over all elements is worse than binary search.

By dividing the array in half, binary search ensures that the size of both subarrays are as similar as possible.

Each iteration of the binary search procedure defined above makes one or two comparisons, checking if the middle element is equal to the target in each iteration.

Assuming that each element is equally likely to be searched, each iteration makes 1. A variation of the algorithm checks whether the middle element is equal to the target at the end of the search.

On average, this eliminates half a comparison from each iteration. This slightly cuts the time taken per iteration on most computers.

However, it guarantees that the search takes the maximum number of iterations, on average adding one iteration to the search. In addition, sorted arrays can complicate memory use especially when elements are often inserted into the array.

Binary search can be used to perform exact matching and set membership determining whether a target value is in a collection of values. There are data structures that support faster exact matching and set membership.

For implementing associative arrays , hash tables , a data structure that maps keys to records using a hash function , are generally faster than binary search on a sorted array of records.

Binary search also supports approximate matches. Some operations, like finding the smallest and largest element, can be done efficiently on sorted arrays but not on hash tables.

A binary search tree is a binary tree data structure that works based on the principle of binary search. The records of the tree are arranged in sorted order, and each record in the tree can be searched using an algorithm similar to binary search, taking on average logarithmic time.

Insertion and deletion also require on average logarithmic time in binary search trees. This can be faster than the linear time insertion and deletion of sorted arrays, and binary trees retain the ability to perform all the operations possible on a sorted array, including range and approximate queries.

However, binary search is usually more efficient for searching as binary search trees will most likely be imperfectly balanced, resulting in slightly worse performance than binary search.

This even applies to balanced binary search trees , binary search trees that balance their own nodes, because they rarely produce optimally -balanced trees.

Binary search trees lend themselves to fast searching in external memory stored in hard disks, as binary search trees can efficiently be structured in filesystems.

The B-tree generalizes this method of tree organization. B-trees are frequently used to organize long-term storage such as databases and filesystems.

Linear search is a simple search algorithm that checks every record until it finds the target value. Linear search can be done on a linked list, which allows for faster insertion and deletion than an array.

Binary search is faster than linear search for sorted arrays except if the array is short, although the array needs to be sorted beforehand.

There are operations such as finding the smallest and largest element that can be done efficiently on a sorted array but not on an unsorted array. A related problem to search is set membership.

Any algorithm that does lookup, like binary search, can also be used for set membership. There are other algorithms that are more specifically suited for set membership.

A bit array is the simplest, useful when the range of keys is limited. It compactly stores a collection of bits , with each bit representing a single key within the range of keys.

For approximate results, Bloom filters , another probabilistic data structure based on hashing, store a set of keys by encoding the keys using a bit array and multiple hash functions.

Bloom filters are much more space-efficient than bit arrays in most cases and not much slower: However, Bloom filters suffer from false positives.

There exist data structures that may improve on binary search in some cases for both searching and other operations available for sorted arrays.

For example, searches, approximate matches, and the operations available to sorted arrays can be performed more efficiently than binary search on specialized data structures such as van Emde Boas trees , fusion trees , tries , and bit arrays.

These specialized data structures are usually only faster because they take advantage of the properties of keys with a certain attribute usually keys that are small integers , and thus will be time or space consuming for keys that lack that attribute.

Some structures, such as Judy arrays, use a combination of approaches to mitigate this while retaining efficiency and the ability to perform approximate matching.

Uniform binary search stores, instead of the lower and upper bounds, the index of the middle element and the change in the middle element from the current iteration to the next iteration.

Each step reduces the change by about half. Uniform binary search works on the basis that the difference between the index of middle element of the array and the left and right subarrays is the same.

The main advantage of uniform binary search is that the procedure can store a table of the differences between indices for each iteration of the procedure.

Uniform binary search may be faster on systems where it is inefficient to calculate the midpoint, such as on decimal computers.

It starts by finding the first element with an index that is both a power of two and greater than the target value. Afterwards, it sets that index as the upper bound, and switches to binary search.

Exponential search works on bounded lists, but becomes an improvement over binary search only if the target value lies near the beginning of the array.

Instead of calculating the midpoint, interpolation search estimates the position of the target value, taking into account the lowest and highest elements in the array as well as length of the array.

This is only possible if the array elements are numbers. It works on the basis that the midpoint is not the best guess in many cases.

For example, if the target value is close to the highest element in the array, it is likely to be located near the end of the array.

In practice, interpolation search is slower than binary search for small arrays, as interpolation search requires extra computation.

Its time complexity grows more slowly than binary search, but this only compensates for the extra computation for large arrays. Fractional cascading is a technique that speeds up binary searches for the same element in multiple sorted arrays.

Fractional cascading was originally developed to efficiently solve various computational geometry problems.

Fractional cascading has been applied elsewhere, such as in data mining and Internet Protocol routing. Noisy binary search algorithms solve the case where the algorithm cannot reliably compare elements of the array.

For each pair of elements, there is a certain probability that the algorithm makes the wrong comparison. Noisy binary search can find the correct position of the target with a given probability that controls the reliability of the yielded position.

In , John Mauchly made the first mention of binary search as part of the Moore School Lectures , a seminal and foundational college course in computing.

Chandra of Stanford University in Guibas introduced fractional cascading as a method to solve numerous search problems in computational geometry.

Although the basic idea of binary search is comparatively straightforward, the details can be surprisingly tricky When Jon Bentley assigned binary search as a problem in a course for professional programmers, he found that ninety percent failed to provide a correct solution after several hours of working on it, mainly because the incorrect implementations failed to run or returned a wrong answer in rare edge cases.

The Java programming language library implementation of binary search had the same overflow bug for more than nine years.

In a practical implementation, the variables used to represent the indices will often be of fixed size, and this can result in an arithmetic overflow for very large arrays.

An infinite loop may occur if the exit conditions for the loop are not defined correctly. In addition, the loop must be exited when the target element is found, or in the case of an implementation where this check is moved to the end, checks for whether the search was successful or failed at the end must be in place.

For searching continuous function values, see bisection method. Take for example the array [1, 2, The first iteration will select the midpoint of 8.

On the left subarray are eight elements, but on the right are nine. If the search takes the right path, there is a higher chance that the search will make the maximum number of comparisons.

An internal path is any path from the root to an existing node. This is because internal paths represent the elements that the search algorithm compares to the target.

The lengths of these internal paths represent the number of iterations after the root node. Adding the average of these lengths to the one iteration at the root yields the average case.

It turns out that the tree for binary search minimizes the internal path length. Knuth proved that the external path length the path length over all nodes where both children are present for each already-existing node is minimized when the external nodes the nodes with no children lie within two consecutive levels of the tree.

When each subtree has a similar number of nodes, or equivalently the array is divided into halves in each iteration, the external nodes as well as their interior parent nodes lie within two levels.

It follows that binary search minimizes the number of average comparisons as its comparison tree has the lowest possible internal path length.

The time complexity for this variation grows slightly more slowly, but at the cost of higher initial complexity. Linear search has lower initial complexity because it requires minimal computation, but it quickly outgrows binary search in complexity.

A modification to the half-interval search binary search method. Archived from the original on 12 March Retrieved 29 June Communications of the ACM.

Journal of the ACM. Retrieved 30 June Procedure is described at p. Journal of Computer and System Sciences.

Archived from the original on 6 March Retrieved 3 April Archived PDF from the original on 22 February

Bloom filters are much more space-efficient than bit arrays in most cases and not much slower: However, Bloom filters suffer from false positives.

There exist data structures that may improve on binary search in some cases for both searching and other operations available for sorted arrays.

For example, searches, approximate matches, and the operations available to sorted arrays can be performed more efficiently than binary search on specialized data structures such as van Emde Boas trees , fusion trees , tries , and bit arrays.

These specialized data structures are usually only faster because they take advantage of the properties of keys with a certain attribute usually keys that are small integers , and thus will be time or space consuming for keys that lack that attribute.

Some structures, such as Judy arrays, use a combination of approaches to mitigate this while retaining efficiency and the ability to perform approximate matching.

Uniform binary search stores, instead of the lower and upper bounds, the index of the middle element and the change in the middle element from the current iteration to the next iteration.

Each step reduces the change by about half. Uniform binary search works on the basis that the difference between the index of middle element of the array and the left and right subarrays is the same.

The main advantage of uniform binary search is that the procedure can store a table of the differences between indices for each iteration of the procedure.

Uniform binary search may be faster on systems where it is inefficient to calculate the midpoint, such as on decimal computers. It starts by finding the first element with an index that is both a power of two and greater than the target value.

Afterwards, it sets that index as the upper bound, and switches to binary search. Exponential search works on bounded lists, but becomes an improvement over binary search only if the target value lies near the beginning of the array.

Instead of calculating the midpoint, interpolation search estimates the position of the target value, taking into account the lowest and highest elements in the array as well as length of the array.

This is only possible if the array elements are numbers. It works on the basis that the midpoint is not the best guess in many cases. For example, if the target value is close to the highest element in the array, it is likely to be located near the end of the array.

In practice, interpolation search is slower than binary search for small arrays, as interpolation search requires extra computation.

Its time complexity grows more slowly than binary search, but this only compensates for the extra computation for large arrays.

Fractional cascading is a technique that speeds up binary searches for the same element in multiple sorted arrays. Fractional cascading was originally developed to efficiently solve various computational geometry problems.

Fractional cascading has been applied elsewhere, such as in data mining and Internet Protocol routing. Noisy binary search algorithms solve the case where the algorithm cannot reliably compare elements of the array.

For each pair of elements, there is a certain probability that the algorithm makes the wrong comparison. Noisy binary search can find the correct position of the target with a given probability that controls the reliability of the yielded position.

In , John Mauchly made the first mention of binary search as part of the Moore School Lectures , a seminal and foundational college course in computing.

Chandra of Stanford University in Guibas introduced fractional cascading as a method to solve numerous search problems in computational geometry.

Although the basic idea of binary search is comparatively straightforward, the details can be surprisingly tricky When Jon Bentley assigned binary search as a problem in a course for professional programmers, he found that ninety percent failed to provide a correct solution after several hours of working on it, mainly because the incorrect implementations failed to run or returned a wrong answer in rare edge cases.

The Java programming language library implementation of binary search had the same overflow bug for more than nine years. In a practical implementation, the variables used to represent the indices will often be of fixed size, and this can result in an arithmetic overflow for very large arrays.

An infinite loop may occur if the exit conditions for the loop are not defined correctly. In addition, the loop must be exited when the target element is found, or in the case of an implementation where this check is moved to the end, checks for whether the search was successful or failed at the end must be in place.

Bentley found that most of the programmers who incorrectly implemented binary search made an error in defining the exit conditions.

For searching continuous function values, see bisection method. Take for example the array [1, 2, The first iteration will select the midpoint of 8.

On the left subarray are eight elements, but on the right are nine. If the search takes the right path, there is a higher chance that the search will make the maximum number of comparisons.

An internal path is any path from the root to an existing node. This is because internal paths represent the elements that the search algorithm compares to the target.

The lengths of these internal paths represent the number of iterations after the root node. Adding the average of these lengths to the one iteration at the root yields the average case.

It turns out that the tree for binary search minimizes the internal path length. Knuth proved that the external path length the path length over all nodes where both children are present for each already-existing node is minimized when the external nodes the nodes with no children lie within two consecutive levels of the tree.

When each subtree has a similar number of nodes, or equivalently the array is divided into halves in each iteration, the external nodes as well as their interior parent nodes lie within two levels.

It follows that binary search minimizes the number of average comparisons as its comparison tree has the lowest possible internal path length.

The time complexity for this variation grows slightly more slowly, but at the cost of higher initial complexity.

Linear search has lower initial complexity because it requires minimal computation, but it quickly outgrows binary search in complexity.

A modification to the half-interval search binary search method. Archived from the original on 12 March Retrieved 29 June Communications of the ACM.

Journal of the ACM. Retrieved 30 June Procedure is described at p. Journal of Computer and System Sciences. Archived from the original on 6 March Retrieved 3 April Archived PDF from the original on 22 February Retrieved 28 March Archived from the original PDF on 4 November Retrieved 26 October Lower bounds for intersection searching and fractional cascading in higher dimension.

Archived PDF from the original on 25 March Archived PDF from the original on 9 August Retrieved 26 September Coping with errors in binary search procedures.

A fast quantum mechanical algorithm for database search. Retrieved 7 May Teaching combinatorial tricks to a computer. Proceedings of Symposia in Applied Mathematics.

A data structuring technique" PDF. Archived PDF from the original on 3 March Retrieved 22 April Applications" PDF , Algorithmica , 1 1: Archived from the original on 1 April Retrieved 21 April Archived PDF from the original on 3 July Retrieved 19 March The Open Group Base Specifications 7th ed.

Archived from the original on 21 March The Go Programming Language. Archived from the original on 25 April Retrieved 28 April Java Platform Standard Edition 8 Documentation.

Archived from the original on 29 April Retrieved 1 May Archived from the original on 23 April BinarySearch method T ".

Archived from the original on 7 May Retrieved 10 April Archived from the original on 17 April Archived from the original on 20 April The Python Standard Library.

Archived from the original on 25 March Retrieved 26 March Diese Zuordnung nennt sich positive Logik , bei negativer Logik werden die Werte andersherum zugeordnet.

Die Ziffernfolge zum Beispiel stellt nicht wie im Dezimalsystem die Tausendeinhunderteins dar, sondern die Dreizehn, denn im Dualsystem berechnet sich der Wert durch.

Die Klammerung der Resultate mit der tiefgestellten 2 beziehungsweise der 10 gibt die Basis des verwendeten Stellenwertsystems an.

So kann leicht erkannt werden, ob die Zahl im Dual- oder im Dezimalsystem dargestellt ist. In der Literatur werden die eckigen Klammern oft weggelassen und die tiefergestellte Zahl dann manchmal in runde Klammern gesetzt.

Verschiedene Schreibweisen der Zahl dreiundzwanzig im Dualsystem:. Der alt-indische Mathematiker Pingala stellte die erste bekannte Beschreibung eines Zahlensystems bestehend aus zwei Zeichen im 3.

Dieses Zahlensystem kannte allerdings keine Null. Der chinesische Gelehrte und Philosoph Shao Yong entwickelte im Jahrhundert daraus eine systematische Anordnung von Hexagrammen, die die Folge von 1 bis 64 darstellt, und eine Methode, um dieselbe zu erzeugen.

Es gibt jedoch keine Hinweise, dass Shao es verstand, Berechnungen im Dualsystem vorzunehmen oder das Konzept des Stellenwertes erkannt hatte.

Schon Jahrhunderte bevor das Dualsystem in Europa entwickelt wurde, haben Polynesier das System zur Vereinfachung von Rechnungen benutzt [2].

Gottfried Wilhelm Leibniz empfand schon Ende des Jahrhunderts die Dyadik dyo, griech. Das Dualsystem wurde von Leibniz am Anfang des Diese Deutung gilt inzwischen als sehr unwahrscheinlich.

Sein logisches System bereitete der Realisierung von elektronischen Schaltkreisen den Weg, welche die Arithmetik im Dualsystem implementieren.

Das Dualsystem ist die einfachste Methode, um mit Zahlen zu rechnen, die durch diese zwei Ziffern dargestellt werden.

Dualzahlen finden in der elektronischen Datenverarbeitung bei der Darstellung von Festkommazahlen oder ganzen Zahlen Verwendung. Negative Zahlen werden vor allem als Zweierkomplement dargestellt, welches nur im positiven Bereich der Dualzahlendarstellung entspricht.

Seltener wird dazu das Einerkomplement verwendet, welches der invertierten Darstellung von Dualzahlen mit vorangestellter Eins entspricht. Eine weitere Alternative bietet der auf einer Wertebereichsverschiebung basierende Exzesscode.

Diese beiden Werte werden dann in Form von Dualzahlen gespeichert. Das geschieht analog zur Dezimaladdition, wenn sich bei der Addition einer Stelle eine Zehn ergibt:.

Alle Ergebnisbits, von rechts nach links aneinandergereiht, stellen das Resultat dar.

## Binäre - think, that

Binäre Sprengstoffe bestehen aus zwei Komponenten, einer festen bzw. Ich will, dass jeder Mensch auf diesem Planeten Zugang zu verständlich aufbereitetem Finanzwissen hat. Der Such-Algorithmus entspricht auch der Suche in einem binären Suchbaum, wenn man das Array als solchen interpretiert: Ansichten Lesen Bearbeiten Quelltext bearbeiten Versionsgeschichte. Das Dualsystem wurde von Leibniz am Anfang des

## 5 thoughts to “Binäre”

1. Voodoozahn says:

Bemerkenswert, es ist das sehr wertvolle StГјck

2. Tojin says:

Ich entschuldige mich, aber meiner Meinung nach sind Sie nicht recht. Ich biete es an, zu besprechen. Schreiben Sie mir in PM, wir werden umgehen.

3. Arajin says:

Wacker, der prГ¤chtige Gedanke

4. Shaktimuro says:

Es kommt mir nicht heran.

5. Akirr says:

Von der ebenen Rechnung nichts.