java实现简单的猜数字小游戏

package Practice;
// 猜数字 (Bulls and cows)
import java.util.Scanner;

public class Day0322 {
 public static void main(String[] args) {
 Scanner scanner = new Scanner(System.in);
 // 产生0000~9999的随机数
 double r = Math.random();
 int res = (int)(r * 8999 + 1000);

 int flag = 0;
 // 合法性检查，判断存在重复数字
 while(flag == 0)
 {
  int[] check = new int[10];
  for(int i = 0; i < 10; i ++ ) check[i] = 0;

  check[res / 1000] += 1;check[(res / 100) % 10] += 1;
  check[(res / 10) % 10] += 1;check[res % 10] += 1;

  for(int i = 0; i < 10; i ++ )
  if(check[i] >= 2) {
   r = Math.random();
   res = (int)(r * 8999 + 1000);
   flag = 0;
   break;
  }
  else flag = 1;
 }

 // 0000~9999
 System.out.println("答案: " + res);

 int input = -1;
 int idx = 0;
 int times = 0;
 while(input != res)
 {
  System.out.print("请输入你猜的数字： ");
  input = scanner.nextInt();
  int inputcopy = input;

  if(input < 0)
  {
  System.out.println("您输入的数字不是四位数！");
  times ++;
  continue;
  }
  int t = 0;
  // 输入数字为4位数，合法性检查
  while(inputcopy != 0)
  {
  inputcopy /= 10;
  t ++;
  }
  if(t != 4)
  {
  System.out.println("您输入的数字不是四位数！");
  times ++;
  continue;
  }

  int n = 0, m = 0;// nAmB

  if(input == res) break;
  // 输入的各个位数
  int[] a = new int[4];
  a[0] = input / 1000;a[1] = (input / 100) % 10;
  a[2] = (input / 10) % 10; a[3] = (input) % 10;
  // 答案的各个位数
  int[] ans = new int[4];
  ans[0] = res / 1000;ans[1] = (res / 100) % 10;
  ans[2] = (res / 10) % 10; ans[3] = (res) % 10;

  for(int i = 0; i < 4; i ++)
  {
  if(ans[i] == a[i]) n += 1; // A的数量
  for(int j = 0; j < 4; j ++){// B的数量
   if(ans[j] == a[i] && j != i) m += 1;
  }
  }
  System.out.print((++ idx) + ": " + n + "A" + m + "B");
  System.out.println();
  times ++;

 }
 if(input == res){
  times ++;
  System.out.println("4A0B");
  System.out.println("你很厉害啊！");
  System.out.println("猜测次数: " + times);
 }

 }

}