利用C++实现计算机辅助教学系统

/*
rand()函数用法：（转载） 
1、rand()不需要参数，它会返回一个从0到最大随机数的任意整数，最大随机数的大小通常是固定的一个大整数。
2、如果你要产生0~99这100个整数中的一个随机整数，可以表达为：int num = rand() % 100; 
这样，num的值就是一个0~99中的一个随机数了。
3、如果要产生1~100，则是这样：int num = rand() % 100 + 1;
4、总结来说，可以表示为：int num = rand() % n +a;
其中的a是起始值，n-1+a是终止值，n是整数的范围。
5、一般性：rand() % (b-a+1)+ a ; 就表示 a~b 之间的一个随机整数。
6、若要产生0-1之间的小数，则可以先取得0-10的整数，然后均除以10即可得到“随机到十分位”的10个随机小数。
若要得到“随机到百分位”的随机小数，则需要先得到0~100的10个整数，然后均除以100，其它情况依 此类推。
*/
#include<iostream>
#include<cmath>
#include <stdlib.h>
using namespace std;
int main()
{
	int x,y,a;  //x和y是两个随机生成的数，a为学生输入的答案 
	int sum=0;  //sum是两个数相乘的结果
	int count=0;//count为计数器 
	int right=0;//记录对的题数
	float s;    //计算正确率 
	do
	{
		count++;
		x=rand()%10;//随机数 
		y=rand()%10;
		sum=x*y;
		cout << x << " * " << y << " = " << endl;
		cout << "Please enter the answer :" << endl;
		cin >> a;
		if(a==sum)
		{
			right++; 
			switch(rand()%4)
			{
				case 0:	cout << "Very good!" << endl << endl;break;
				case 1:	cout << "Excellent!" << endl << endl;break;
				case 2:	cout << "Nice work!" << endl << endl;break;
				case 3:	cout << "Keep up the good work!" << endl << endl;break;
			}
		}
		else
		{
			switch(rand()%4)
			{	
				case 0:	cout << "No. Please try again." << endl << endl;break;
				case 1:	cout << "Wrong. Try once more." << endl << endl;break;
				case 2:	cout << "Don't give up!" << endl << endl;break;
				case 3:	cout << "No. Keep trying." << endl << endl;break;
			}
		}
	}while(count<10);
	s=right*1.0/count;//计算正确率 
	if(s<0.75)
	{
		cout <<"Please ask your instructor foe extra help" << endl;
	}
	return 0;
}

#include<iostream>
#include<cmath>
#include <stdlib.h>
using namespace std;
int main()
{
	int x,y,a;  //x和y是两个随机生成的数，a为学生输入的答案 
	int sum=0;  //sum是两个数相乘的结果
	int count=0;//count为计数器 
	int right=0;//记录对的题数
	float s;    //计算正确率 
	int note=0;//记录能力等级 
	int f=0;//记录用户所希望学的问题 
	cout << "Please enter your ability level, 1 or 2" << endl;
	cin >> note; 
	cout << endl;
	cout << "************" << endl;
	cout << "*1:加法问题*" << endl; 
	cout << "*2:减法问题*" << endl; 
	cout << "*3:乘法问题*" << endl;
	cout << "*4:除法问题*" << endl;
	cout << "************" << endl;
	cout << "Please enter the type of arithmetic problem you want to learn" << endl;
	cin >> f;
	do
	{
	        count++;
		if(note==1)
		{			
			x=rand()%10;//随机数 
			y=rand()%10;
		}
		else
		{
			x=rand()%20;//随机数 
			y=rand()%20;
		}
		if(f==1)
		{
			sum=x+y;
			cout << x << " + " << y << " = " << endl;
		}
		else if(f==2)
		{
			sum=x-y;
			cout << x << " - " << y << " = " << endl;
		}
		else if(f==3)
		{
			sum=x*y;
			cout << x << " * " << y << " = " << endl;
		}
		else if(f==4)
		{
			sum=x/y;
			cout << x << " / " << y << " = " << endl;
		}
			cout << "Please enter the answer :" << endl;
			cin >> a;
			if(a==sum)
			{
				right++; 
				switch(rand()%4)
				{
					case 0:	cout << "Very good!            " << endl << endl;break;
					case 1:	cout << "Excellent!            " << endl << endl;break;
					case 2:	cout << "Nice work!            " << endl << endl;break;
					case 3:	cout << "Keep up the good work!" << endl << endl;break;
				}
			}
			else
			{
				switch(rand()%4)
				{	
					case 0:	cout << "No. Please try again." << endl << endl;break;
					case 1:	cout << "Wrong. Try once more." << endl << endl;break;
					case 2:	cout << "Don't give up!       " << endl << endl;break;
					case 3:	cout << "No. Keep trying.     " << endl << endl;break;
				}
			}
	}while(count<10);
	s=right*1.0/count;//计算正确率 
	if(s<0.75)
	{
		cout <<"Please ask your instructor foe extra help !!!" << endl;
	}
	return 0;
}