下面的代码确实按照我需要的方式工作,但它很丑,过多或其他一些事情。我已经看了公式,并试图写一些解决方案,但我最终得到了类似数量的语句。

在这种情况下,是否有一种数学公式对我有益,或者是否可以接受16个if语句?

为了解释代码,这是一款基于同时回合制的游戏。两名玩家各有四个操作按钮,结果来自一个数组(0-3),但变量“1”和“2”可以赋值任何东西,如果这有帮助的话。结果是,0 =双方都不赢,1 = p1赢,2 = p2赢,3 =双方都赢。

public int fightMath(int one, int two) {

    if(one == 0 && two == 0) { result = 0; }
    else if(one == 0 && two == 1) { result = 0; }
    else if(one == 0 && two == 2) { result = 1; }
    else if(one == 0 && two == 3) { result = 2; }
    else if(one == 1 && two == 0) { result = 0; }
    else if(one == 1 && two == 1) { result = 0; }
    else if(one == 1 && two == 2) { result = 2; }
    else if(one == 1 && two == 3) { result = 1; }
    else if(one == 2 && two == 0) { result = 2; }
    else if(one == 2 && two == 1) { result = 1; }
    else if(one == 2 && two == 2) { result = 3; }
    else if(one == 2 && two == 3) { result = 3; }
    else if(one == 3 && two == 0) { result = 1; }
    else if(one == 3 && two == 1) { result = 2; }
    else if(one == 3 && two == 2) { result = 3; }
    else if(one == 3 && two == 3) { result = 3; }

    return result;
}

当前回答

静态int val(int i, int u){ Int q = (i & 1) ^ (u & 1); 返回(i >> 1) << (1 ^ q))|((u >> 1) << q); }

其他回答

静态int val(int i, int u){ Int q = (i & 1) ^ (u & 1); 返回(i >> 1) << (1 ^ q))|((u >> 1) << q); }

如果你无法想出一个公式,你可以使用一个表格来描述有限的结果:

final int[][] result = new int[][] {
  { 0, 0, 1, 2 },
  { 0, 0, 2, 1 },
  { 2, 1, 3, 3 },
  { 1, 2, 3, 3 }
};
return result[one][two];

相反,你可以这样做

   public int fightMath(int one, int two) {
    return Calculate(one,two)

    }


    private int Calculate(int one,int two){

    if (one==0){
        if(two==0){
     //return value}
    }else if (one==1){
   // return value as per condtiion
    }

    }

我个人喜欢级联三元运算符:

int result = condition1
    ? result1
    : condition2
    ? result2
    : condition3
    ? result3
    : resultElse;

但在你的情况下,你可以使用:

final int[] result = new int[/*16*/] {
    0, 0, 1, 2,
    0, 0, 2, 1,
    2, 1, 3, 3,
    1, 2, 3, 3
};

public int fightMath(int one, int two) {
    return result[one*4 + two];
}

或者,你可以注意到比特的模式:

one   two   result

section 1: higher bits are equals =>
both result bits are equals to that higher bits

00    00    00
00    01    00
01    00    00
01    01    00
10    10    11
10    11    11
11    10    11
11    11    11

section 2: higher bits are different =>
lower result bit is inverse of lower bit of 'two'
higher result bit is lower bit of 'two'

00    10    01
00    11    10
01    10    10
01    11    01
10    00    10
10    01    01
11    00    01
11    01    10

所以你可以使用魔法:

int fightMath(int one, int two) {
    int b1 = one & 2, b2 = two & 2;
    if (b1 == b2)
        return b1 | (b1 >> 1);

    b1 = two & 1;

    return (b1 << 1) | (~b1);
}

为什么不使用数组呢?

我将从头说起。我看到了一个模式,值从0到3,你想捕捉所有可能的值。这是你的桌子:

0 & 0 = 0
0 & 1 = 0
0 & 2 = 1
0 & 3 = 2
1 & 0 = 0
1 & 1 = 0
1 & 2 = 2
1 & 3 = 1
2 & 0 = 2
2 & 1 = 1
2 & 2 = 3
2 & 3 = 3
3 & 0 = 2
3 & 1 = 1
3 & 2 = 3
3 & 3 = 3

当我们查看相同的二进制表时,我们看到以下结果:

00 & 00 = 00
00 & 01 = 00
00 & 10 = 01
00 & 11 = 10
01 & 00 = 00
01 & 01 = 00
01 & 10 = 10
01 & 11 = 01
10 & 00 = 10
10 & 01 = 01
10 & 10 = 11
10 & 11 = 11
11 & 00 = 10
11 & 01 = 01
11 & 10 = 11
11 & 11 = 11

现在你可能已经看到了一些模式,但当我把值1和2结合起来时,我看到你使用了所有的值0000,0001,0010,.....1110和1111。现在让我们把值1和值2组合成一个4位整数。

0000 = 00
0001 = 00
0010 = 01
0011 = 10
0100 = 00
0101 = 00
0110 = 10
0111 = 01
1000 = 10
1001 = 01
1010 = 11
1011 = 11
1100 = 10
1101 = 01
1110 = 11
1111 = 11

当我们把它转换回十进制值时,我们看到一个非常可能的值数组,其中1和2的组合可以用作索引:

0 = 0
1 = 0
2 = 1
3 = 2
4 = 0
5 = 0
6 = 2
7 = 1
8 = 2
9 = 1
10 = 3
11 = 3
12 = 2
13 = 1
14 = 3
15 = 3

数组是{0,0,1,2,0,0,2,1,2,1,2,1,3,3,2,1,3,3,1,3,3},其中它的索引是1和2的组合。

我不是Java程序员,但你可以去掉所有的if语句,把它写下来,就像这样:

int[] myIntArray = {0, 0, 1, 2, 0, 0, 2, 1, 2, 1, 3, 3, 2, 1, 3, 3};
result = myIntArray[one * 4 + two]; 

我不知道移位2是否比乘法快。但这值得一试。