// 模拟摸球 500 回，每回 3 次，摸到 1、3、5、7 为白球， 2、4、6、8 为红球
#include<stdio.h>
#include<time.h>
#define N 500.0

int main(void)
{
    int ball[3];
    int ball_white;
    int ball_red;
    int i;
   
    ball_white=ball_red=0;
    srand(time(NULL));
    for(i=0;i<500;++i)
    {
        int j;
        int k;
        for(j=0;j<3;++j)
        {
            ball[j]=rand()%7+1;
            for(k=0;k<j;++k)
            {
                if(ball[j]==ball[k])
                {
                    --j;
                    break;
                }
            }
        }
        for(j=k=0;j<3;++j)
        {
            if(ball[j]%2)
            {
                ++k;
            }
            else
            {
                --k;
            }
            printf("%3d",ball[j]);
        }
        puts("");
        if(k==3)
        {
            ++ball_white;
        }
        if(k==-3)
        {
            ++ball_red;
        }
    }
    printf("while=%d\tred=%d\n",ball_white,ball_red);
    printf("白球机率为%.2f\t红球机率为%.2f\n",(ball_white/N)*100,(ball_red/N)*100);
   
    return 0;
}