importjava.util.*;publicclassMain{staticint count=0;publicvoidPerm(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);}}}publicvoidSwap(int[] list,int i,int j){int t = list[i];
list[i]= list[j];
list[j]= t;}publicstaticvoidmain(String[] args){Main d =newMain();int[] arr ={1,2,3,4};d.Perm(arr,0,3);System.out.println("全排列为"+count+"种");}}