个人项目3：可以在之前基础上实现在线答题；

答题结束后可以判断对错；

可以将错题保存起来；

程序：

#include<iostream.h>

#include<stdlib.h>

#include<time.h>

void boom()

{

float x,y;

int a,b;

int first_num,second_num,third_num,fourth_num;

srand(time(NULL));

int n;

float k;

float d;

float daan[100];

int zq=0;

int cw=0;

cout<<"所需题数"<<endl;

cin>>n;

for(int i=0;i<n;i++)

{

a=rand()%4;

first_num=rand()%10;

second_num=rand()%10;

third_num=rand()%10;

fourth_num=rand()%10;

if (second_num==1)

{

x=(float)first_num;

}

else if(first_num>second_num)

{

b=first_num;

first_num=second_num;

second_num=b;

}

x=(float)first_num/second_num;

if (fourth_num==1)

{

y=(float)third_num;

}

else if(third_num>fourth_num)

{

b=third_num;

third_num=fourth_num;

fourth_num=b;

}

y=(float)third_num/fourth_num;

a=rand()%4;

switch(a)

{

case 0:

cout<<i+1<<"、 "<<first_num<<"/"<<second_num<<"+"<<third_num<<"/"<<fourth_num<<"="<<" ";

daan[i+1]=x+y;

break;

case 1:

cout<<i+1<<"、 "<<first_num<<"/"<<second_num<<"-"<<third_num<<"/"<<fourth_num<<"="<<" ";

daan[i+1]=x-y;

break;

case 2:

cout<<i+1<<"、 "<<first_num<<"/"<<second_num<<"*"<<third_num<<"/"<<fourth_num<<"="<<" ";

daan[i+1]=x*y;

break;

case 3:

if(y!=0)

{

cout<<i+1<<"、 "<<first_num<<"/"<<second_num<<"÷"<<third_num<<"/"<<fourth_num<<"="<<" ";

}

else

{

i=i-1;

}

daan[i+1]=(float)x/y;

break;

}

if((i+1)%3==0)

{

for(int c=0;c<=1;c++)

{

cout<<endl;

}

}

if((i+1)==n)

{

cout<<endl;

}

}

for(i=1;i<=n;i++)

{

cout<<"请答题:"<<endl;

cout<<i<<"、";

cin>>d;

if(d==daan[i])

{

cout<<"回答正确！"<<endl;

cout<<endl;

zq=zq+1;

}

else

{

cout<<"回答错误，正确答案为："<<" "<<daan[i]<<endl;

cout<<endl;

cw=cw+1;

}

}

k=(float)zq/n;

cout<<"答对数为："<<" "<<zq<<"个"<<endl;

cout<<"答错数为："<<" "<<cw<<"个"<<endl;

cout<<"正确率为："<<" "<<k<<endl;

}

int main()

{

boom();

main();

return 0;

}

运行结果：

出现的问题：

不知如何将错题保存，以及以什么形式保存。