C语言求对数

求以2为底，x的对数：

#include

int main()

{

int x;

int ret = 0;

scanf("%d", &x);

int t = x;

while ( x > 1 ) {

x /= 2;

ret ++;

}

printf("log2 of %d is %d.", t, ret);

return 0;

}