Java 数组索引超出范围-将2d转换为1d
我不太清楚为什么会出现数组索引越界异常。据我所知,我的双数组大小为3,因此索引从0到2。在我的isSolvable方法中,我尝试计算我的双数组中的反转数,其中反转是任何一对块I和j,其中IJava 数组索引超出范围-将2d转换为1d,java,arrays,multidimensional-array,indexoutofboundsexception,dimensional,Java,Arrays,Multidimensional Array,Indexoutofboundsexception,Dimensional,我不太清楚为什么会出现数组索引越界异常。据我所知,我的双数组大小为3,因此索引从0到2。在我的isSolvable方法中,我尝试计算我的双数组中的反转数,其中反转是任何一对块I和j,其中I
int N = 3;
static int [][] copy;
//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){
blocks = new int[N][N]; //creates array of size N
//generates random numbers 0 inclusive to # exclusive
//creates ArrayList - shuffle used to prevent repeating of numbers
List<Integer> randomList = new ArrayList<>();
for (int i = 0; i < 9; i++){
randomList.add(i);
}
int counter = 0;
Collections.shuffle(randomList);
for (int i = 0; i < blocks.length; i++){
for (int j = 0; j < blocks[i].length; j++){
blocks[i][j] = randomList.get(counter);
counter++;
}
}
copy = blocks.clone();
}
//is the board solvable?
public boolean isSolvable(){
int inversions = 0;
List<Integer> convert = new ArrayList<>(); // used to convert 2d to 1d
for (int i = 0; i < copy.length; i++){
for (int j = 0; i < copy[i].length; j++){
convert.add(copy[i][j]); //ARRAYINDEXOUTOFBOUNDSEXCEPTION: 3
}
}
for (int i = 0; i < copy.length; i++){ //counts the number of inversions
if (convert.get(i) < convert.get(i-1)){
inversions++;
}
}
if (inversions % 2 == 0){
return true; //even
}
return false; //odd
}
//unit test
public static void main(String[] args){
//prints out board
printArray();
Board unittest = new Board(copy);
unittest.isSolvable(); //ARRAYINDEXOUTOFBOUNDSEXCEPTION: 3
}
int N=3;
静态int[][]拷贝;
//从N×N块阵列构造电路板
//(其中块[i][j]=第i行第j列中的块)
公用电路板(int[][]块){
blocks=newint[N][N];//创建大小为N的数组
//生成包含0到#互斥的随机数
//创建用于防止数字重复的ArrayList-shuffle
List randomList=新建ArrayList();
对于(int i=0;i<9;i++){
随机列表。添加(i);
}
int计数器=0;
集合。随机移动(随机列表);
对于(int i=0;i
您在可解决的内部循环中有一个输入错误
:
for (int j = 0; i < copy[i].length; j++){
^
|
should be j
for(int j=0;i
应该是:
for (int j = 0; j < copy[i].length; j++){
for(int j=0;j
您在可解决的内部循环中有一个输入错误
:
for (int j = 0; i < copy[i].length; j++){
^
|
should be j
for(int j=0;i
应该是:
for (int j = 0; j < copy[i].length; j++){
for(int j=0;j
数组索引j
超出范围,因为您在检查i
时不断增加j
的值。由于该值保持为真,j将增加到数组copy[i][j]的索引超出范围的数字
数组索引j
将越界,因为您在检查i
时不断增加j
的值。由于该值保持为真,j将增加到一个数字,该数字是数组copy[i][j]的越界索引