课堂测试小程序

题目：随机数的四则运算

思路：取两个随机整数，将运算符号放在一个数组里，再取一个随机数，整除4，通过余数来选取预算符号。真分数的四则运算，要取四个随机整数，并进行大小判断，真分数的分母要大于其分子。

代码：

#include<iostream>
#include<time.h>
using namespace std;
void main()
{
srand(time(NULL));
for (int i = 1; i <= 30; i++)
{
int a = rand()%25+1;
int b = rand()%25+1;
int c = rand() % 25 + 1;
int d = rand() % 25 + 1;
int e = a % 2;
int f = b % 4;
int x[4] = { '+', '-', '*', '/' };
int y = 0;
if (e == 1 && b < a&&d < c)
{
if (f == 1)

cout << b << '/' << a << ' ' << '+' << ' ' << d << '/' << c << "=" << endl;

else if (f == 2)

cout << b << '/' << a << ' ' << '-' << ' ' << d << '/' << c << "=" << endl;

else if (f == 3)

cout << b << '/' << a << ' ' << '*' << ' ' << d << '/' << c << "=" << endl;

else

cout << b << '/' << a << ' ' << '/' << ' ' << d << '/' << c << "=" << endl;
}

else
{
if (f == 1)
{
y = a + b;
cout << a << '+' << b << "=" << endl;
}
else if (f == 2)
{
y = a - b;
cout << a << '-' << b << "=" << endl;
}
else if (f == 3)
{
y = a * b;
cout << a << '*' << b << "=" << endl;
}
else
{
y = b / a;
cout << b << '/' << a << "=" << endl;
}
}

}
}

测试结果：



感受：通过这次小测试，我明白了“分解”思想的重要性。