Bitwise operation

Bitwise operation

Setting k-th bit of x:       x |= 1 [shift] k
    Clearing k-th bit:       x &= ~(1 [shift] k)
     Getting k-th bit:       return (x [shift] k) & 1
    Flipping k-th bit:       x ^= 1 [shift] k  (replaces 0 by 1, and 1 by 0.)

ex: 10311 - Goldbach and Euler
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