n& (n-1)

1. Determine if a positive integer is a number of 2

Data comparison (uint_16 N;)

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Binary representation of a positive integer n positive integer n (n-1) positive integer (n-1) binary represents n& (n-1)

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2 0000000000000010 1) 0000000000000001 00000 00000000000

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4 0000000000000100 3) 0000000000000011 00000 00000000000

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- 0000000000010000 15 0000000000001111 00000 00000000000

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- 0000000001100100 0000000001100011 0000000001100000

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- 0000000010 000000 127 0000000001 11111 1 0000000000000000

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unsigned char ispower (unsigned int N)

{    return (0)  | | (N & (n10x000x01);}

2. Determine the number of the number "1" When a positive integer is converted to binary

Char int N) {    char0;      while (n)    {        &= n1;        I++    ;    } return i;}

n& (n-1)