Bitwise operations

Flip Bits

Determine the number of bits required to flip if you want to convert integer n to integer m.

I feel glad to come up solution on this and pass the OJ with one pass. It might be easy, but it's from here I gain confidence on bitwise operations.

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public static int bitSwapRequired(int a, int b) { // write your code here int c = a^b; //1.xor operation leave difference with 1s //2. n&(n-1) will remove last 1 int cnt=0; while(c!=0){ cnt++; c = c&(c-1); } return cnt; }

Check power of 2

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public boolean checkPowerOf2(int n) { // write your code here //n&(n-1) will remove last 1, 2's power has only one 1 in it return (n>=1&&(n&(n-1))==0); }