# include <stdio.h>

int main(void)
{
    int x ,y ,z ,a ,s ,d;
   
    a=5,s=3,d=1;

    printf("设公鸡x个，母鸡y个，小鸡z个。\n");
    printf("公鸡一只5钱，母鸡一只3钱，小鸡三只1钱。\n");
   
    for    (x=1,x*a<=100,x+=1)
        {
        for    (y=1,x*a+y*s<=100,y+=1)
            {
            for(z=1,x*a+y*s+z*d<=100,z+=1)
                {
                    if(x*a+y*s+z*d==100 || x+y+z*3==100)
                    {
                        z*=3
                        printf("x=%d,y=%d,z=%d",x,y,z);
                        printf("公鸡%d只,母鸡%d只,小鸡%d只",x,y,z);
                    }
                }
            }
        }
   
   
    return 0;
}

error C2146: syntax error : missing ';' before identifier 'printf'
Error executing cl.exe.
系统提示是这样的。

错误有4处，3个for循环里面是；
还有一处没if里面第一条后面加；
就是四个；的问题

已经看到了，我可真是粗心，不过还是谢谢了，已经改好了
# include <stdio.h>

int main(void)
{
    int x ,y ,z ,a ,s ,d ,n;
   
    a=5,s=3,d=1,n=0;

    printf("设公鸡x个，母鸡y个，小鸡z个。\n");
    printf("公鸡一只5钱，母鸡一只3钱，小鸡三只1钱。\n");
   
    for    (x=0;x*a<=100;x+=1)
        {
        for    (y=0;x*a+y*s<=100;y+=1)
            {
            for(z=0;x*a+y*s+z*d<=100;z+=1)
                {
                    if(x*a+y*s+z*d==100 && x+y+z*3==100)
                    {
                        n+=1;
                        z*=3;
                        printf("第%d种结果，如下。\n",n);
                        printf("x=%d,y=%d,z=%d\n",x,y,z);
                        printf("公鸡%d只,母鸡%d只,小鸡%d只\n",x,y,z);
                        
                    }
                }
            }
        }
   
   
    return 0;
}

嗯，好

其实很多地方都是小失误造成的
所以写代码要严谨啊