你问我为啥要写，只是觉得随机生成数比较好玩吧，上课老师也说了一下，可以减轻家长负担！！！
#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
using namespace std;
int main()
{
int n = 0;
while (n != 4) {
srand((unsigned)time(NULL));//生成随机数必备
cout << "***********************************" << endl;
cout << "* 欢迎你来到四则运算系统 *" << endl;
cout << "* 输入1您将来到四则运算生成表 *" << endl;
cout << "* 输入2您将来到四则运算现场测试 *" << endl;
cout << "* 输入3您将来到家长检查模式 *" << endl;
cout << "* 输入4您将结束本次训练 *" << endl;
cout << "***********************************" << endl;
cin >> n;
if (n == 1) {
int m; int s;
cout << "请您输入您要打印的公式数量：" << endl;
cin >> m;
cout << "请您输入您要选择计算的范围为0到多少：" << endl;
cin >> s;
char C;
int A[2000], B[2000];
int a[2000];
int i, k, t, h, T;
t = 0; T = 0; h = 1;
for (i = 0; i < m; i++)
{
k = rand() % 4;//产生四个随机数字，从而产生四个随机符号。
if (k == 0)
C = '+';
else if (k == 1)
C = '-';
else if (k == 2)
C = '*';
else if (k == 3)
C = '/';
A[i] = rand() % s;
B[i] = rand() % s + 1;//除数不能为0，这是关键，系统会崩溃的
//输出题目
if (C == '+')
{
cout << "第" << h << "道：" << A[i] << "+" << B[i] << "=" << endl; a[i] = A[i] + B[i];
h++;
}
else if (C == '-')
{
cout << "第" << h << "道：" << A[i] << "-" << B[i] << "=" << endl; a[i] = A[i] - B[i];
h++;
}
else if (C == '*')
{
cout << "第" << h << "道：" << A[i] << "X" << B[i] << "=" << endl; a[i] = A[i] * B[i];
h++;
}
else if (C == '/')
{
cout << "第" << h << "道：" << A[i] << "÷" << B[i] << "=" << endl; a[i] = A[i] / B[i];
h++;
}
}
cout << "************************" << endl;
//输出四则运算的结果
for (int i = 0; i < m; i++) {
cout << "第" << i + 1 << "题的答案为：" << a[i] << endl;
}
}
if (n == 2) {
int t = 10; int t1;
cout << "随机训练马上就要开始了，你准备好了吗？" << endl;
cout << "请您输入您要选择计算的范围为0到多少：" << endl;
cin >> t1;
while (t != -1) {
cout << "*****************" << endl;
cout << "输入1继续开始训练" << endl;
cout << "输入-1结束训练" << endl;
cin >> t;
if (t == 1) {
char C;
int A, B, F;
double D;
int i, k, t, h, T;
t = 0; T = 0; h = 1;
k = rand() % 4;//产生四个随机数字，从而产生四个随机符号。
if (k == 0) {
C = '+';
}
else if (k == 1)
{
C = '-';
}
else if (k == 2)
{
C = '*';
}
else if (k == 3)
{
C = '/';
}
A = rand() % t1;
B = rand() % t1 + 1;
//输出题目
if (C == '+')
{
cout << A << "+" << B << "=" << endl; D = A + B;
}
else if (C == '-')
{
cout << A << "-" << B << "=" << endl; D = A - B;
}
else if (C == '*')
{
cout << A << "X" << B << "=" << endl; D = A * B;
}
else if (C == '/')
{
cout << A << "÷" << B << "=" << endl; D = A / B;
}
cin >> F;
if (F == D) {
cout << "答案正确，你太棒了！" << endl;
}
else {
cout << "答案错误，正确答案为：" << D << endl;
}
}
}
}
if (n == 3) {
int m;
int s;
cout << "欢迎来到家长模式" << endl;
cout << "请您输入您要打印的公式数量：" << endl;
cin >> m;
cout << "请您输入您要选择计算的范围为0到多少：" << endl;
cin >> s;
int A[2000], B[2000], i, k, t, T, a[2000], b[2000], c[2000], d[2000];
char C;
srand((unsigned)time(NULL));
t = 0; T = 0;
for (i = 0; i < m; i++)
{
k = rand() % 4;
if (k == 0)
C = '+';
else if (k == 1)
C = '-';
else if (k == 2)
C = '*';
else if (k == 3)
C = '/';
A[i] = rand() % s;
B[i] = rand() % s + 1;
//输出题目
if (C == '+')
{
cout << "第" << i + 1 << "道题：" << A[i] << "+" << B[i] << "=" << endl; a[i] = A[i] + B[i];
}
else if (C == '-')
{
cout << "第" << i + 1 << "道题：" << A[i] << "-" << B[i] << "=" << endl; a[i] = A[i] - B[i];
}
else if (C == '*')
{
cout << "第" << i + 1 << "道题：" << A[i] << "X" << B[i] << "=" << endl; a[i] = A[i] * B[i];
}
else if (C == '/')
{
cout << "第" << i + 1 << "道题：" << A[i] << "÷" << B[i] << "=" << endl; a[i] = A[i] / B[i];
}
}
//输出结果
cout << "**********************" << endl;
for (i = 0; i < m; i++)
{
cout << "第" << i + 1 << "道题结果为：";
cin >> b[i];
if (a[i] == b[i])
t++;
else
{
c[T] = i;
d[T] = a[i];
T++;
}
}
cout << "**********************" << endl;
if (t == m)
cout << "恭喜你都答对了！" << endl;
else
{
for (i = 0; i < T; i++)
cout << "第" << c[i] + 1 << "题错了！" << "正确答案应该是：" << d[i] << endl;
}
}
if (n > 4) {
cout << "您输入的数字错误，请重新输入！" << endl;
}
}
}好歹也写了3个小时，调试起来还很麻烦，随机水一篇，也运用了数组的很多方面吧，就是喜欢做这种简单的系统，水一天啦，话说map的系统还没做......
