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;
}
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];
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; }
}
}
下面是一个相当简洁的版本,类似于JAB的回应。这使用地图来存储哪个移动战胜其他移动。
public enum Result {
P1Win, P2Win, BothWin, NeitherWin;
}
public enum Move {
BLOCK_HIGH, BLOCK_LOW, ATTACK_HIGH, ATTACK_LOW;
static final Map<Move, List<Move>> beats = new EnumMap<Move, List<Move>>(
Move.class);
static {
beats.put(BLOCK_HIGH, new ArrayList<Move>());
beats.put(BLOCK_LOW, new ArrayList<Move>());
beats.put(ATTACK_HIGH, Arrays.asList(ATTACK_LOW, BLOCK_LOW));
beats.put(ATTACK_LOW, Arrays.asList(ATTACK_HIGH, BLOCK_HIGH));
}
public static Result compare(Move p1Move, Move p2Move) {
boolean p1Wins = beats.get(p1Move).contains(p2Move);
boolean p2Wins = beats.get(p2Move).contains(p1Move);
if (p1Wins) {
return (p2Wins) ? Result.BothWin : Result.P1Win;
}
if (p2Wins) {
return (p1Wins) ? Result.BothWin : Result.P2Win;
}
return Result.NeitherWin;
}
}
例子:
System.out.println(Move.compare(Move.ATTACK_HIGH, Move.BLOCK_LOW));
打印:
P1Win
除了JAB之外,我不喜欢任何提出的解决方案。其他方法都不容易阅读代码和理解正在计算的内容。
以下是我如何编写这段代码——我只会c#,不懂Java,但你可以想象:
const bool t = true;
const bool f = false;
static readonly bool[,] attackResult = {
{ f, f, t, f },
{ f, f, f, t },
{ f, t, t, t },
{ t, f, t, t }
};
[Flags] enum HitResult
{
Neither = 0,
PlayerOne = 1,
PlayerTwo = 2,
Both = PlayerOne | PlayerTwo
}
static HitResult ResolveAttack(int one, int two)
{
return
(attackResult[one, two] ? HitResult.PlayerOne : HitResult.Neither) |
(attackResult[two, one] ? HitResult.PlayerTwo : HitResult.Neither);
}
现在,这里计算的内容更加清楚了:这强调了我们正在计算谁受到了什么攻击,并返回两个结果。
然而,这可能会更好;布尔数组有点不透明。我喜欢表格查找方法,但我更倾向于以一种能够明确游戏语义的方式来编写它。也就是说,与其“攻击为零,防御为一,结果是没有命中”,不如找到一种方法,让代码更清楚地暗示“低踢攻击和低阻挡防御,结果是没有命中”。让代码反映游戏的业务逻辑。
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。