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Commit933848b

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Add more bit manipulation functions.
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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, multiplication/division by two etc.
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*`B`[Bit Manipulation](src/algorithms/math/bits) - set/get/update/clear bits, multiplication/division by two, make negative 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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Powers of two: 2^3 + 0 + 2^1 + 0
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```
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>See`multiplyByTwo` function for further details.
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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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Number: 0b0010 = 2
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Powers of two: 0 + 0 + 2^1 + 0
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```
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>See`divideByTwo` function for further details.
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####Switch Sign
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This method make positive numbers to be negative and backwards.
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To do so it uses "Twos Complement" approach which does it by
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inverting all of the bits of the number and adding 1 to it.
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```
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1101 -3
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1110 -2
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1111 -1
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0000 0
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0001 1
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0010 2
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0011 3
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```
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>See`switchSign` function for further details.
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##References
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-[Bit Manipulation on YouTube](https://www.youtube.com/watch?v=NLKQEOgBAnw&t=0s&index=28&list=PLLXdhg_r2hKA7DPDsunoDZ-Z769jWn4R8)
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-[Negative Numbers in binary on YouTube](https://www.youtube.com/watch?v=4qH4unVtJkE&t=0s&index=30&list=PLLXdhg_r2hKA7DPDsunoDZ-Z769jWn4R8)
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-[Bit Hacks on stanford.edu](https://graphics.stanford.edu/~seander/bithacks.html)
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importswitchSignfrom'../switchSign';
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describe('switchSign',()=>{
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it('should switch the sign of the number using twos complement approach',()=>{
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expect(switchSign(0)).toBe(0);
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expect(switchSign(1)).toBe(-1);
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expect(switchSign(-1)).toBe(1);
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expect(switchSign(32)).toBe(-32);
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expect(switchSign(-32)).toBe(32);
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expect(switchSign(23)).toBe(-23);
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expect(switchSign(-23)).toBe(23);
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});
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});
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/**
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* Switch the sign of the number using "Twos Complement" approach.
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*@param {number} number
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*@return {number}
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*/
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exportdefaultfunctionswitchSign(number){
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return~number+1;
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}

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