C Language: Bit operation Small example several

First, I'll enumerate some of the commonly used operators associated with bit operations in C.

First, shift operators

Left shift operator <<

The arithmetic left shift and the logical left shift are all left-hand, and the right side is 0;

Right shift operator >>

The logical right moves to the right to the left of the highest bit 0, while the arithmetic right moves to the right to move out one bit, and the highest bit to fill the symbol bit.

Second, bitwise operators

and &

Algorithm: See 0 is 0, all 1 is 1;

or |

Algorithm: See 1 is 1, all 0 is 0;

Xor ^

Algorithm: The same 0, the difference is 1;

Next I'll share a few more common programming examples of bitwise manipulation

1. Do not use temporary variables to achieve the exchange of numbers a and b

#include <stdao.h>int main () {int a=2;aint b=3;a=a^b;b=a^b;a=a^b;printf ("a=%d,b=%d\n", A, b);     return 0;} 2. Do not use (A+B)/2 This way, the average value of two numbers #include <stdio.h>int fun (int x, int y) {Int ret  = 0;ret =  (X & y)  +  ((x  ^ y)  >> 1 );//printf ("%d\n",  ret);} Int main () {        int a, b;printf ("Please enter two number: \ n"); scanf_s ("%d %d",  &a, &b); fun (a, b); return  0;} 3. Find the number of 1 in the binary number//method one #include <stdio.h>int main () {         int x;int count=0;scanf_s ("%d",  &x);while  (x)     {         x = x& (x - 1);               count++;    }printf ("%D\n ", count); return  0;} Method two #include <stdio.h>int  count_one_bits (Int value)//  returns the number of bits of  1 {// 1111111111111111111int count = 0;int i = 0;    for (i =  0;i<32;i++) {if (value & 1 == 1) count++;value = value >>  1;} Return count;}

int main ()

{

printf ("%d\n", Count_one_bits (-1));

return 0;

}

This article is from the "Molova" blog, make sure to keep this source http://molova.blog.51cto.com/10594266/1684499

C Language: Bit operation Small example several