我正在努力学习Java，我正在挑战自己重写“2048”游戏（如果你不知道它是如何工作的那样看看here）
所以我有一个名为'mat'的4x4矩阵，其中包含4个方向移动数字的游戏编号和4种方法：
private int[][] mat = new int[4][4];
和movingUp方法：
private boolean MoveUp() {
System.out.println("Moving Up");
boolean nextRow;
boolean moved = false;
for(int j = 0; j < 4; j++){
boolean[] collapsed = new boolean[3];
do{
nextRow = true;
for(int i = 0; i < 3; i++){
if((mat[i][j] == 0) && (mat[i+1][j] != 0)){
mat[i][j] = mat[i+1][j];
mat[i+1][j] = 0;
nextRow = false;
moved = true;
} else if((mat[i][j] != 0) && (mat[i][j] == mat[i+1][j]) && !collapsed[i] && !collapsed[i+1]){
mat[i][j] += mat[i+1][j];
mat[i+1][j] = 0;
collapsed[i] = true;
nextRow = false;
moved = true;
}
}
} while(!nextRow);
}
return moved;
}
但是经过一些比赛后我得到了这个输出：
---------------------
| | | | |
| | | | 4|
| | | | |
|----|----|----|----|
| | | | |
| | 2| 8| 64|
| | | | |
|----|----|----|----|
| | | | |
| | | 4| 32|
| | | | |
|----|----|----|----|
| | | | |
| | | 8| 32|
| | | | |
---------------------
w
Moving Up
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 3
at Game.MoveUp(Game.java:91)
at Game.Move(Game.java:35)
at Game.<init>(Game.java:14)
at Game.main(Game.java:210)
我真的不明白为什么，任何人都可以帮助我？ ：）
以下是完整代码：
import java.util.Scanner;
public class Game {
private int[][] mat = new int[4][4];
private boolean gameover = false;
public Game(){
GenRand();
GenRand();
do{
PrintMat();
Move();
gameover = CheckGameover();
if(!gameover) GenRand();
} while(!gameover);
System.out.println("Game Over!");
}
private void Move(){
boolean done = false;
do{
Scanner in = new Scanner(System.in);
char input = in.next().charAt(0);
switch(input){
case ('a'):
done = MoveLeft();
break;
case ('d'):
done = MoveRight();
break;
case ('w'):
done = MoveUp();
break;
case ('s'):
done = MoveDown();
break;
default: System.out.println("Wrong Input");
}
} while(!done);
}
private boolean MoveDown() {
System.out.println("Moving Down");
boolean nextRow;
boolean moved = false;
for(int j = 0; j < 4; j++){
boolean[] collapsed = new boolean[4];
do{
nextRow = true;
for(int i = 3; i > 0; i--){
if((mat[i][j] == 0) && (mat[i-1][j] != 0)){
mat[i][j] = mat[i-1][j];
mat[i-1][j] = 0;
nextRow = false;
moved = true;
} else if((mat[i][j] != 0) && (mat[i][j] == mat[i-1][j]) && !collapsed[i] && !collapsed[i-1]){
mat[i][j] += mat[i-1][j];
mat[i-1][j] = 0;
collapsed[i] = true;
nextRow = false;
moved = true;
}
}
} while(!nextRow);
}
return moved;
}
private boolean MoveUp() {
System.out.println("Moving Up");
boolean nextRow;
boolean moved = false;
for(int j = 0; j < 4; j++){
boolean[] collapsed = new boolean[3];
do{
nextRow = true;
for(int i = 0; i < 3; i++){
if((mat[i][j] == 0) && (mat[i+1][j] != 0)){
mat[i][j] = mat[i+1][j];
mat[i+1][j] = 0;
nextRow = false;
moved = true;
} else if((mat[i][j] != 0) && (mat[i][j] == mat[i+1][j]) && !collapsed[i] && !collapsed[i+1]){
mat[i][j] += mat[i+1][j];
mat[i+1][j] = 0;
collapsed[i] = true;
nextRow = false;
moved = true;
}
}
} while(!nextRow);
}
return moved;
}
private boolean MoveRight() {
System.out.println("Moving Right");
boolean nextRow;
boolean moved = false;
for(int i = 0; i < 4; i++){
boolean[] collapsed = new boolean[4];
do{
nextRow = true;
for(int j = 3; j > 0; j--){
if((mat[i][j] == 0) && (mat[i][j-1] != 0)){
mat[i][j] = mat[i][j-1];
mat[i][j-1] = 0;
nextRow = false;
moved = true;
} else if((mat[i][j] != 0) && (mat[i][j] == mat[i][j-1]) && !collapsed[j] && !collapsed[j-1]){
mat[i][j] += mat[i][j-1];
mat[i][j-1] = 0;
collapsed[j] = true;
nextRow = false;
moved = true;
}
}
} while(!nextRow);
}
return moved;
}
public boolean MoveLeft(){
System.out.println("Moving Left");
boolean nextRow;
boolean moved = false;
for(int i = 0; i < 4; i++){
boolean[] collapsed = new boolean[3];
do{
nextRow = true;
for(int j = 0; j < 3; j++){
if((mat[i][j] == 0) && (mat[i][j+1] != 0)){
mat[i][j] = mat[i][j+1];
mat[i][j+1] = 0;
nextRow = false;
moved = true;
} else if((mat[i][j] != 0) && (mat[i][j] == mat[i][j+1]) && !collapsed[j] && !collapsed[j+1]){
mat[i][j] += mat[i][j+1];
mat[i][j+1] = 0;
collapsed[j] = true;
nextRow = false;
moved = true;
}
}
} while(!nextRow);
}
return moved;
}
private boolean CheckGameover(){
System.out.println("Checking Gameover");
for(int i = 0; i < 4; i++){
for(int j = 0; j < 4; j++){
if(mat[i][j] == 0) return false;
else if((i != 0) && (mat[i][j] == mat[i-1][j])) return false;
else if((i != 3) && (mat[i][j] == mat[i+1][j])) return false;
else if((j != 0) && (mat[i][j] == mat[i][j-1])) return false;
else if((j != 3) && (mat[i][j] == mat[i][j+1])) return false;
}
}
return true;
}
private void GenRand(){
boolean done = false;
while(!done){
int n = (int)(Math.random() * 4);
int m = (int)(Math.random() * 4);
if(mat[n][m] == 0){
mat[n][m] = ((int)((Math.random() *2) + 1) *2); //Random 2 or 4
done = true;
}
}
}
private void PrintMat() {
System.out.println("---------------------");
System.out.println("| | | | |");
for(int i = 0; i < 4; i++) {
for(int j = 0; j < 4; j++) {
if(mat[i][j] != 0) System.out.print(String.format("|%4d", mat[i][j]));
else System.out.print("| ");
}
System.out.println("|\n| | | | |");
if(i != 3) {
System.out.println("|----|----|----|----|");
System.out.println("| | | | |");
} else {
System.out.println("---------------------");
}
}
}
public static void main(String[] args) {
Game newGame = new Game();
}
}
更新： 我有另一个问题：我从未进入“游戏结束！”，可能checkGameover（）方法不起作用，但我找不到原因......
答案 0 :(得分：1)
看起来问题是：
boolean[] collapsed = new boolean[3];
的尺寸应为4，而不是3。