随机4个数看是否能通过加减乘除算出24
using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace ConsoleApplication1{ class Program { static void Main(string[] args) { Operation text = new Operation(); text.Opr(); Console.Read(); } } public class Operation { int num = 4; //数组里元素的个数 int Number = 0; string str1 = null; string str2 = null; public void Opr() { //初始化数组 Random r1 = new Random(); int[] r2 = { 4, 4, 4, 4 }; for (int j = 0; j < 4; j++) { int a = 0; a = r1.Next(0, 10); r2[j] = a; } Console.Write("随机的四个数为{0},{1},{2},{3}", r2[0], r2[1], r2[2], r2[3]); Console.WriteLine(); getNumber(num, r2); } public void getNumber(int num,int []r) { for (int i = 0; i < num; i++) { for (int j = 0; j < num && j != i; j++) { if(num == 4) { for (int k = 0; k < 4; k++) { switch (k) { case 0: Number = r[i] + r[j]; str1 = r[i].ToString() + "+" + r[j].ToString() + "=" + Number; show(i, j, Number, r, num); break; case 1: Number = r[i] - r[j]; str1 = r[i].ToString() + "-" + r[j].ToString() + "=" + Number; show(i, j, Number, r, num); break; case 2: Number = r[i] * r[j]; str1 = r[i].ToString() + "*" + r[j].ToString() + "=" + Number; show(i, j, Number, r, num); break; case 3: if (r[j] != 0) { Number = r[i] / r[j]; str1 = r[i].ToString() + "/" + r[j].ToString(); show(i, j, Number, r,num); } break; } } } if (num == 3) { for (int k = 0; k < 4; k++) { switch (k) { case 0: Number = r[i] + r[j]; str2 = r[i].ToString() + "+" + r[j].ToString() + "=" + Number; show(i, j, Number, r,num); break; case 1: Number = r[i] - r[j]; str2 = r[i].ToString() + "-" + r[j].ToString() + "=" + Number; show(i, j, Number, r,num); break; case 2: Number = r[i] * r[j]; str2 = r[i].ToString() + "*" + r[j].ToString() + "=" + Number; show(i, j, Number, r,num); break; case 3: if (r[j] != 0) { Number = r[i] / r[j]; str2 = r[i].ToString() + "/" + r[j].ToString() + "=" + Number; show(i, j, Number, r,num); } break; } } } if (num == 2) { for (int k = 0; k < 4; k++) { switch (k) { case 0: Number = r[i] + r[j]; if (Number == 24) { Console.Write("第一步" + str1 + "第二步 " + str2 + "第三步" + r[i] + "+" + r[j] + "=" + Number); } break; case 1: Number = r[i] - r[j]; if (Number == 24) { Console.Write("第一步" + str1 + "第二步 " + str2 + "第三步" + r[i] + "-" + r[j] + "=" + Number); } break; case 2: Number = r[i] * r[j]; if (Number == 24) { Console.Write("第一步" + str1 + "第二步 " + str2 + "第三步" + r[i] + "*" + r[j] + "=" + Number); } break; case 3: if (r[j] != 0) { Number = r[i] / r[j]; } if (Number == 24) { Console.Write("第一步" + str1 + "第二步 " + str2 + "第三步" + r[i] + "/" + r[j] + "=" + Number); } break; } } } } } } public void show(int i,int j,int Number,int []r,int num) { int[] a = new int[3]; int b = 0; for(int m=0;m<num;m++) { if (m != i && m != j) { a[b++] = r[m]; } } a[b] = Number; num = num - 1; getNumber(num, a); } }}
