我正在使用普林斯顿提出的algs4 8-puzzle程序。我在第二个for循环中得到一个数组索引超出范围的异常。有没有人看到引发此异常的问题?我的板类+相关方法如下所示:
public class Board {
private final int[][] blocks;
private final int N;
// construct a board from an N-by-N array of blocks
// (where blocks[i][j] = block in row i, column j)
public Board(int[][] blocks){
N = blocks.length;
this.blocks = new int[N][];
for (int i=0; i<N; i++){
this.blocks[i] = Arrays.copyOf(blocks[i], N);
}
}
// board dimension N
public int dimension(){
return this.N;
}
//is the board solvable?
public boolean isSolvable(){
int inversions = 0;
List<Integer> convert = new ArrayList<>(); // convert 2d to 1d
for (int i = 0; i < blocks.length; i++){
for (int j = 0; j < blocks[i].length; j++){
convert.add(blocks[i][j]);
}
}
for (int i = 0; i < blocks.length; i++){ //counts the number of inversions
if (convert.get(i) < convert.get(i-1)){ //ARRAYINDEXOUTOFBOUNDS -1
inversions++;
}
}
if (inversions % 2 == 0){
return true; //even
}
return false; //odd
}
答案 0 :(得分:1)
convert.get(i-1)
超出范围。
您应该更改循环的起始索引:
for (int i = 1; i < blocks.length; i++){ //counts the number of inversions
if (convert.get(i) < convert.get(i-1)){
inversions++;
}
}