全排列问题（Java）

import java.util.*;
public class Main { 
static int count=0;
public void Perm(int list[], int k, int m) {
      if (k == m) {
      for (int i = 0; i <= m; i++)
      System.out.print(list[i]);
      System.out.println();
      count++;    
   }
      else{
      for (int i = k; i <= m; i++) {
      Swap(list, k, i);
      Perm(list, k + 1, m);
      Swap(list, k, i);
      }
   }
}  
public void Swap(int[] list, int i, int j) {
      int t = list[i];
      list[i] = list[j];
      list[j] = t;
      }
public static void main(String[] args) {
       Main d = new Main();
       int[] arr = {1,2,3,4};
       d.Perm(arr, 0, 3);
       System.out.println("全排列为"+count+"种");
       }
    }