输出一个序列的全排列

#include <stdio.h>void swap(int &a,int &b){ int t; t = a; a = b; b = t;}void cal(int* arr,int low,int high){ int i; if(low==high) {  for(i =0; i <= high; i++)   printf("%d\t",arr[i]); } else { for(i = low; i <= high; i++) {  swap(arr[low],arr[i]);  cal(arr,low+1,high);  swap(arr[low],arr[i]);  } }}int main(){ int  arr[]={1,2,3}; cal(arr,0,2); return 0;}