using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;namespace 四则运算
{public partial class Form1 : Form{int i, j;char[] fh = { '＋', '－', '×', '÷' };// char[] fs = { ' ', '-' };public Form1(){InitializeComponent();}static int GetRandomSeed()  //随机数种子，解决随机数一致问题
        {byte[] bytes = new byte[4];System.Security.Cryptography.RNGCryptoServiceProvider rng = new System.Security.Cryptography.RNGCryptoServiceProvider();rng.GetBytes(bytes);return BitConverter.ToInt32(bytes, 0);}private void button1_Click(object sender, EventArgs e){i = int.Parse(textBox1.Text);//获取题数j = int.Parse(textBox2.Text);//获取运算符数int m = 0;Random rd = new Random(GetRandomSeed());int n=1;for (int a = 0; a < i; a++){if (checkBox2.Checked == true){m = input_qkh(m, n);input_num();for (int b = 0; b < j; b++){input_fh();//input_fs();if (b < j - n) { m = input_qkh(m, n); }input_num();m = input_hkh(m, n);//input(" ");
}input("=\n");}else {input_num();for (int b = 0; b < j; b++){input_fh();// input_fs();
                            input_num();// input(" ");
                        }input("=\n");}}}public void input_num(){int a = int.Parse(textBox4.Text);int b = int.Parse(textBox5.Text);if (checkBox3.Checked == true){Random rd = new Random(GetRandomSeed());int c = rd.Next(2);int num1 = rd.Next(a, b + 1);int num2 = rd.Next(0, b + 1);switch (c){case 0: {input(num1.ToString());input("/");input(num2.ToString());} break;case 1: input(num1.ToString()); break;}}else{Random rd = new Random(GetRandomSeed());int num1 = rd.Next(a, b + 1);input(num1.ToString());}}public int input_qkh(int m,int n)//（前括号）m为判定有无前括号，n为后括号添加位置
        {Random rd = new Random(GetRandomSeed());if(m == 0)                //判定有无前括号
            {int a = rd.Next(2);if (a == 0)     //随机概率添加前括号{ input("(");m = 1;}}else{}// input("m=" + m.ToString());return m;}public int input_hkh(int m, int n)//（后括号）m为判定有无前括号，n为后括号添加位置
        {Random rd = new Random(GetRandomSeed());if (m == 0)                //判定有无前括号
            {}else{if (m == n + 1){input(")");m = 0;}else{ m++; }}//   input("m="+m.ToString());return m;}/*public void input_fs(){if (checkBox1.Checked == true){Random rd = new Random(GetRandomSeed());input(fs[rd.Next(2)].ToString());//符号}else {input(" ");}}*/public void input_fh(){if (checkBox4.Checked == true){Random rd = new Random(GetRandomSeed());input(fh[rd.Next(4)].ToString());//符号
            }else {Random rd = new Random(GetRandomSeed());input(fh[rd.Next(2)].ToString());//符号
            }}private void button2_Click(object sender, EventArgs e){textBox3.Text = "";textBox1.Text = "";textBox2.Text = "";textBox4.Text = "";textBox5.Text = "";}public void input(string t){textBox3.AppendText(t);}}
}