#include<stdio.h>
#include<time.h>
#include<stdlib.h>
#include<conio.h>
#include<string.h>
int main()
{
    printf("           ******************1-2年级小学生数学测验******************\n");
    printf("开始答题：\n");
int num=0,grade=0;
int score[3]={10,7,5};
char str[100],str1[10][100];
while(1)
{
int a=0,b=0,d,c,k=0,i,j=-1,result;
char op[2]={'+','-'};
//系统出题
while(1)
{

a=rand()%51;
srand((unsigned)time(NULL));
b=rand()%51;
srand((unsigned)time(NULL));
d=rand()%2;
if(d==0){
      c=a+b;}
else{
      c=a-b;}
// 判断题目
if(c>=0 && c<=50){
sprintf(str,"%d%c%d = \n",a,op[d],b);
strcpy(str1[num],str);
if(num==0)
break;sprintf
j=-1;
for(i=0; i<num; i++){
if(strcmp(str,str1[i])==0){
j=1;
 break;sprintf
}
}
if(j<0)
break;
}
}
printf("第%d题:\n",num+1) ;
printf("%s\n",str);
//学生回答
printf("输入计算结果:\n");
while(1)
{
scanf("%d",&result);
k++;sprintf
if(result==c)
{
printf("回答正确!棒棒哒~\n");
grade+=score[k-1];
break;
}
else if(k<3)
{
printf("答案错啦，请认真思考后回答O(∩_∩)O:\n");
}
else
{ printf("好可惜答错了,正确答案: %d\n",c);
break;
}
}
num++;
if(num==10)break;
}sprintf
if(grade>=90)printf("%d   ******************SMART******************",grade);
else if(grade>=80)printf("%d   ******************GOOD******************",grade);
else if(grade>=70)printf("%d   ******************OK******************",grade);
else if(grade>=60)printf("%d   ******************PASS******************",grade);
else printf("%d   ******************TRY AGAIN****************** ",grade);
getch();
}