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

既然您更喜欢嵌套的if条件,这里有另一种方法。 注意,它没有使用result成员,也没有改变任何状态。

public int fightMath(int one, int two) {
    if (one == 0) {
      if (two == 0) { return 0; }
      if (two == 1) { return 0; }
      if (two == 2) { return 1; }
      if (two == 3) { return 2; }
    }   
    if (one == 1) {
      if (two == 0) { return 0; }
      if (two == 1) { return 0; }
      if (two == 2) { return 2; }
      if (two == 3) { return 1; }
    }
    if (one == 2) {
      if (two == 0) { return 2; }
      if (two == 1) { return 1; }
      if (two == 2) { return 3; }
      if (two == 3) { return 3; }
    }
    if (one == 3) {
      if (two == 0) { return 1; }
      if (two == 1) { return 2; }
      if (two == 2) { return 3; }
      if (two == 3) { return 3; }
    }
    return DEFAULT_RESULT;
}

其他回答

((two&2)*(1+((one^two)&1))+(one&2)*(2-((one^two)&1)))/2

既然您更喜欢嵌套的if条件,这里有另一种方法。 注意,它没有使用result成员,也没有改变任何状态。

public int fightMath(int one, int two) {
    if (one == 0) {
      if (two == 0) { return 0; }
      if (two == 1) { return 0; }
      if (two == 2) { return 1; }
      if (two == 3) { return 2; }
    }   
    if (one == 1) {
      if (two == 0) { return 0; }
      if (two == 1) { return 0; }
      if (two == 2) { return 2; }
      if (two == 3) { return 1; }
    }
    if (one == 2) {
      if (two == 0) { return 2; }
      if (two == 1) { return 1; }
      if (two == 2) { return 3; }
      if (two == 3) { return 3; }
    }
    if (one == 3) {
      if (two == 0) { return 1; }
      if (two == 1) { return 2; }
      if (two == 2) { return 3; }
      if (two == 3) { return 3; }
    }
    return DEFAULT_RESULT;
}

使用常量或枚举使代码更具可读性 尝试将代码拆分为更多的函数 试着利用问题的对称性

这里是一个建议,但在这里使用int型仍然有点难看:

static final int BLOCK_HIGH = 0;
static final int BLOCK_LOW = 1;
static final int ATTACK_HIGH = 2;
static final int ATTACK_LOW = 3;

public static int fightMath(int one, int two) {
    boolean player1Wins = handleAttack(one, two);
    boolean player2Wins = handleAttack(two, one);
    return encodeResult(player1Wins, player2Wins); 
}



private static boolean handleAttack(int one, int two) {
     return one == ATTACK_HIGH && two != BLOCK_HIGH
        || one == ATTACK_LOW && two != BLOCK_LOW
        || one == BLOCK_HIGH && two == ATTACK_HIGH
        || one == BLOCK_LOW && two == ATTACK_LOW;

}

private static int encodeResult(boolean player1Wins, boolean player2Wins) {
    return (player1Wins ? 1 : 0) + (player2Wins ? 2 : 0);
}

使用结构化类型作为输入和输出会更好。输入实际上有两个字段:位置和类型(阻挡或攻击)。输出也有两个字段:player1Wins和player2Wins。将其编码为单个整数会使代码更难阅读。

class PlayerMove {
    PlayerMovePosition pos;
    PlayerMoveType type;
}

enum PlayerMovePosition {
    HIGH,LOW
}

enum PlayerMoveType {
    BLOCK,ATTACK
}

class AttackResult {
    boolean player1Wins;
    boolean player2Wins;

    public AttackResult(boolean player1Wins, boolean player2Wins) {
        this.player1Wins = player1Wins;
        this.player2Wins = player2Wins;
    }
}

AttackResult fightMath(PlayerMove a, PlayerMove b) {
    return new AttackResult(isWinningMove(a, b), isWinningMove(b, a));
}

boolean isWinningMove(PlayerMove a, PlayerMove b) {
    return a.type == PlayerMoveType.ATTACK && !successfulBlock(b, a)
            || successfulBlock(a, b);
}

boolean successfulBlock(PlayerMove a, PlayerMove b) {
    return a.type == PlayerMoveType.BLOCK 
            && b.type == PlayerMoveType.ATTACK 
            && a.pos == b.pos;
}

不幸的是,Java并不擅长表达这类数据类型。

试试开关外壳……

看看这里或这里关于它的更多信息

switch (expression)
{ 
  case constant:
        statements;
        break;
  [ case constant-2:
        statements;
        break;  ] ...
  [ default:
        statements;
        break;  ] ...
}

您可以向它添加多个条件(不是同时添加),甚至可以在没有满足其他情况的情况下添加默认选项。

PS:只有在满足一个条件的情况下。

如果两种情况同时出现。我认为开关不能用。 但是您可以减少这里的代码。

Java开关语句多种情况

感谢@Joe Harper,因为我最终使用了他的答案的变体。为了进一步瘦身,每4个结果中有2个是相同的,我进一步瘦身。

我可能会在某个时候回到这个问题上,但如果没有由多个if语句引起的主要阻力,那么我现在就保留这个问题。我将进一步研究表格矩阵和开关语句解决方案。

public int fightMath(int one, int two) {
  if (one === 0) {
    if (two === 2) { return 1; }
    else if(two === 3) { return 2; }
    else { return 0; }
  } else if (one === 1) {
    if (two === 2) { return 2; }
    else if (two === 3) { return 1; }
    else { return 0; }
  } else if (one === 2) {
    if (two === 0) { return 2; }
    else if (two === 1) { return 1; }
    else { return 3; }
  } else if (one === 3) {
    if (two === 0) { return 1; }
    else if (two === 1) { return 2; }
    else { return 3; }
  }
}