/**
 * file: main.c
 * author: 简单教程(www.twle.cn)
 *
 * Copyright © 2015-2065 www.twle.cn. All rights reserved.
 */

#include <stdlib.h>
#include <stdio.h>

int main()
{
    int i,n;
    for(i=1;i<5;i++)
    {
        n=0;
        if(i!=1)
            n=n+1;
        if(i==3)
            n=n+1;
        if(i==4)
            n=n+1;
        if(i!=4)
            n=n+1;
        if(n==3)
            printf("%c\n",64+i);
    }
}

C