Bulls and Cows的Java求解过程遇到的问题

2020.04.16

Note1

  Java创建链表：

List<int[]> numberList = new ArrayList<int[]>();

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Note2

  Java格式化创建字符串：

String str=String.format("[%d; %d; %d; %d]", c[0], c[1], c[2], c[3]);

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简单策略解法

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

public class Main {

    private static List<int[]> numberList;


    public static void main(String[] args) {

        InitNumberList();
        int size=numberList.size();
        System.out.println(size);
        for(int i=0;i<size;i++){
            InitNumberList();
            String str=Print(numberList.get(i));
            int step=GuessIt(numberList.get(i));
            if(step>8)
                System.out.printf("%d %d %s\n",i,step,str);
        }


    }

    public static int GuessIt(int[] result)
    {
        int a = 0;
        int b = 0;
        int step = 0;
        while (a != 4)
        {
            int[] currentNumber = numberList.get(0);
            a = GetA(result, currentNumber);
            b = GetAB(result, currentNumber) - a;
            RemoveA(a, currentNumber);
            RemoveAB(a + b, currentNumber);
//            System.out.printf("Current Guess: %s, Return: %dA%dB, The Result Is: %s\n",
//                    Print(currentNumber), a, b, Print(result));
            step++;
        }
        //System.out.printf("Step: %d\n", step);
        return step;
    }

    public static String Print(int[] c)
    {
        return String.format("[%d; %d; %d; %d]", c[0], c[1], c[2], c[3]);
    }

    public static void InitNumberList(){
        numberList = new ArrayList<int[]>();
        Set hs = new HashSet();
        for (int a = 0; a <= 9; a++) {
            hs.add(a);
            for (int b = 0; b <= 9; b++) {
                if (hs.contains(b))
                    continue;
                hs.add(b);
                for (int c = 0; c <= 9; c++) {
                    if (hs.contains(c))
                        continue;
                    hs.add(c);
                    for (int d = 0; d <= 9; d++){
                        if (hs.contains(d))
                            continue;
                        numberList.add(new int[]{a, b, c, d});
                    }
                    hs.remove(c);
                }
                hs.remove(b);
            }
            hs.remove(a);
        }
    }

    public static int GetA(int[] number, int[] guessNumber)
    {
        int count = 0;
        for (int i = 0; i < 4; i++)
            if (number[i] == guessNumber[i]) count++;
        return count;
    }

    public static int GetAB(int[] number, int[] guessNumber)
    {
        int count = 0;
        for (int i = 0; i < 4; i++)
            for (int j = 0; j < 4; j++)
                if (number[i] == guessNumber[j]) count++;
        return count;
    }

    public static void RemoveA(int a, int[] guessNumber)
    {
        for (int k = numberList.size() - 1; k >= 0; k--)
        {
            if (GetA(numberList.get(k), guessNumber) != a)
                numberList.remove(k);
        }
    }

    public static void RemoveAB(int ab, int[] guessNumber)
    {
        for (int k = numberList.size() - 1; k >= 0; k--)
        {
            if (GetAB(numberList.get(k), guessNumber) != ab)
                numberList.remove(k);
        }
    }

}