計算一個數的對數

# include<stdio.h>
# include<stdbool.h>

int main()
{
    int x;
    int ret = 0;
    
    scanf("%d", &x);
    
    int t = x;
    
    while(x>1){
        x/=2;
        ret++;
    }
    
    printf("log2(%d)=%d\n", t, ret);
    
    return 0;
    
}