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Commitc268203

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Add more bit manipulation functions.
1 parent792f490 commitc268203

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6 files changed

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6 files changed

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‎README.md

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@@ -49,7 +49,7 @@ a set of rules that precisely define a sequence of operations.
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###Algorithms by Topic
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***Math**
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*`B`[Bit Manipulation](src/algorithms/math/bits) - set/get/update/clear bits
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*`B`[Bit Manipulation](src/algorithms/math/bits) - set/get/update/clear bits, multiplication/division by two etc.
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*`B`[Factorial](src/algorithms/math/factorial)
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*`B`[Fibonacci Number](src/algorithms/math/fibonacci)
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*`B`[Primality Test](src/algorithms/math/primality-test) (trial division method)

‎src/algorithms/math/bits/README.md

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This method is a combination of "Clear Bit" and "Set Bit" methods.
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>See`updateBit` function for further details.
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####Multiply By Two
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This method shifts original number by one bit to the left.
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Thus all binary number components (powers of two) are being
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multiplying by two and thus the number itself is being
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multiplied by two.
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```
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Before the shift
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Number: 0b0101 = 5
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Powers of two: 0 + 2^2 + 0 + 2^0
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After the shift
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Number: 0b1010 = 10
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Powers of two: 2^3 + 0 + 2^1 + 0
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```
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####Divide By Two
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This method shifts original number by one bit to the right.
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Thus all binary number components (powers of two) are being
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divided by two and thus the number itself is being
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divided by two without remainder.
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```
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Before the shift
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Number: 0b0101 = 5
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Powers of two: 0 + 2^2 + 0 + 2^0
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After the shift
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Number: 0b0010 = 2
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Powers of two: 0 + 0 + 2^1 + 0
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```
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importdivideByTwofrom'../divideByTwo';
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describe('divideByTwo',()=>{
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it('should divide numbers by two using bitwise operations',()=>{
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expect(divideByTwo(0)).toBe(0);
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expect(divideByTwo(1)).toBe(0);
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expect(divideByTwo(3)).toBe(1);
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expect(divideByTwo(10)).toBe(5);
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expect(divideByTwo(17)).toBe(8);
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expect(divideByTwo(125)).toBe(62);
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});
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});
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importmultiplyByTwofrom'../multiplyByTwo';
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describe('multiplyByTwo',()=>{
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it('should multiply numbers by two using bitwise operations',()=>{
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expect(multiplyByTwo(0)).toBe(0);
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expect(multiplyByTwo(1)).toBe(2);
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expect(multiplyByTwo(3)).toBe(6);
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expect(multiplyByTwo(10)).toBe(20);
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expect(multiplyByTwo(17)).toBe(34);
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expect(multiplyByTwo(125)).toBe(250);
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});
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});
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/**
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*@param {number} number
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*@return {number}
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*/
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exportdefaultfunctiondivideByTwo(number){
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returnnumber>>1;
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}
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/**
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*@param {number} number
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*@return {number}
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*/
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exportdefaultfunctionmultiplyByTwo(number){
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returnnumber<<1;
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}

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