程序代码：

#include <stdio.h>
#include <time.h>

int main (void) {
        srand((unsigned)time(NULL));
        int i,ma=0,mb=0;
        for(i=0;i<20;i++) {
                ma+=rand()%2;
                mb+=rand()%2;
                if(ma==11) {
                        printf("player a won!\na score is %i,b socre is %i\n",ma,mb);
                        return 0;
                }
                if(mb==11) {
                        printf("player b won!\nb score is %i,a score is %i\n",mb,ma);
                        return 0;
                }
        }
        printf("player a score is %i\nplayer b score is %i\n",ma,mb);
        if((ma-mb)>2)
                printf("player a won!\n");
        else if((mb-ma)>2)
                printf("player b won!\n");
        else
                printf("game result is Draw!\n");
        return 0;
}