java怎么搞全排列

尽量用递归好理解一些,打个断点
public class Permutation {

public static void permulation(int[] list, int start, int length) {
int i;
if (start == length) {
for (i = 0; i < length; i++)
System.out.print(list[i] + " ");
System.out.println();
} else {
for (i = start; i < length; i++) {
swap(list, start, i);
permulation(list, start + 1, length);
swap(list, start, i);
}
}
}

public static void swap(int[] list, int start, int i) {
int temp;
temp = list[start];
list[start] = list[i];
list[i] = temp;
}

public static void main(String[] args) {
int length = 3;
int start = 0;
int list[] = new int[length];
for (int j = 0; j < length; j++)
list[j] = j + 1;
permulation(list, start, length);
}

}

i==s.length的时候数组会越界