编辑代码

#include <stdio.h>

#include <stdbool.h>
bool IsOdd(int num)
{
    return num & 1 == 1;
}

int mul2(int num)
{
    return num << 1;
}

int main () {
    int n = 253;

    bool bret = IsOdd(n);

    if (bret)
    {
        printf("odd number\n");
    }
    else
    {
        printf("even number\n");
    }

    int n1 = 2;

    int ret = mul2(n1);

    printf("ret : %d\n", ret);

    return 0;
}