bits operartions

bits.cpp

short val = 12;

// check if bit is set:
if (val & 0b0010) return true;

// ensure bit is 1:
val = val | 0b0010;

// ensure bit is o:
val = val & ~0b0010;

// toogle bit:
val = val ^ 0b0010;

int numOfSetBits(int val) {
    if (val == 0) return 0;
    return (val & 01) ? 1 + numOfSetBits(val >> 1) : numOfSetBits(val >> 1);
}

bool isEven(int val) {
    return (val & 0x01 == 1) ? false : true;
}

bool isPowerOfTwo(int val) {
    return ((val & (val-1)) == 0) ? true : false;
//    return ((val & (-val)) == val) ? true : false;
}

void swap(int *a, int *b) {
  *a = *a ^ *b;
  *b = *a ^ *b;
  *a = *a ^ *b;
}