Java实现n位数字的全排列

public class Test {
static int k=0;
public static void main(String[] args) {
  int a[]={1,2,3,4,5};
  permutations(a,0,4);
}
public static void permutations(int[]a,int m,int n){
  if(m==n){
    k++;
    System.out.print(k+"个:");
    for(int i=0;i<=n;i++){
      System.out.print(a[i]);
    }
    System.out.println();
  }else{
    for(int i=m;i<=n;i++){
      int temp=a[m];
      a[m]=a[i];
      a[i]=temp; 
      permutations(a,m+1,n);
      temp=a[m];
      a[m]=a[i];
      a[i]=temp;
    }
  }
}