/*随机输出2个数算法--Apxar*/
/*随机输出2个数算法--Apxar*/
#include<stdio.h>
#include<stdlib.h>
#include<time.h>
int main(void)
{

int i,j,k=2,num1,num2,sum=0,answer,score=0,xiabiao,temp;
 char fuhao[2]={'+','-'};
 srand((int)time(0));

 for(i=1;i<=10;i++)
 {
 
xiabiao=rand()%2;
 num1=rand()*50/32767;
 num2=rand()*50/32767;
if(xiabiao==0)
{ sum=num1+num2;}
 else
{ sum=num1-num2;} 
 
 if(sum>=0&&sum<=50)
{
j=2; k=1;

 printf("\n(%d).\n",i);
 printf("%7d\n",num1);
 printf("%c\n",fuhao[xiabiao]);
 printf("%7d\n",num2);
 printf("------------\n");
 printf("请输入正确答案 ");
 scanf("%d",&answer);

 if(sum==answer)

 {
 printf("\n结果:你输入的答案正确! \n\n");
 score+=10;
 }

 else
 {
 while(j<=3)
{
 printf("\n答案错误,请重新输入:");
 scanf("%d",&answer);
if(sum==answer)
 {
printf("\n结果:你输入的答案正确! \n\n");
k++;
 
if(k==2)
{ score+=7;}
 else if(k==3)
{ score+=5;}

 break;

}
 else

 { k++;}
 j++;

}
 if(j>3)
printf("\n该题正确答案为:%d\n",sum);

}

}
 else

 i--;
 }
 printf("\n共%d道题目,你的总分为%d\n \n",i-1,score);
}