Add countBitsToflipAToB (trekhleb#154)

Author: tapaswenipathak

Diff for: src/algorithms/math/bits/README.md

@@ -91,6 +91,20 @@ inverting all of the bits of the number and adding 1 to it.
 
 > See `switchSign` function for further details.
 
+#### Count Bits to Flip One Number to Another
+
+This methods outputs the number of bits required to convert a number to another. This
+makes use of property that when numbers are XORed the result will be number of different
+bits and `countSetBits`.
+
+``
+Number A : 5 = (0101)_2
+Number B : 1 = (0001)_2
+Count Bits to be Flipped: 1
+``
+
+> See `countBitsToflipAToB` function for further details.
+
 #### Multiply Two Numbers
 
 This method multiplies two integer numbers using bitwise operators.
@@ -129,6 +143,7 @@ Count of set bits = 2
 
 > See `countSetBits` function for further details.
 
+
 ## References
 
 - [Bit Manipulation on YouTube](https://www.youtube.com/watch?v=NLKQEOgBAnw&t=0s&index=28&list=PLLXdhg_r2hKA7DPDsunoDZ-Z769jWn4R8)

Diff for: src/algorithms/math/bits/countBitsToflipAToB.js

@@ -0,0 +1,11 @@
+import countSetBits from 'countSetBits';
+
+/**
+ * @param {number} number
+ * @return {number}
+ */
+export default function countBitsToflipAToB(numberA, numberB) {
+
+  return countSetBits(numberA ^ numberB);
+
+}