全排列函数 next_permutation && prev-permutation

#include<iostream>
#include<stdio.h>
#include<string.h>
using namespace std;
int main()
{
int a[10]={1,2,3};
do
{
  cout<<a[0]<<" "<<a[1]<<" "<<a[2]<<endl;                            
}while(next_permutation(a,a+3));
cout<<endl<<"--------"<<endl<<endl; 
int  aa[10]={3,2,1};
do
{
  cout<<aa[0]<<" "<<aa[1]<<" "<<aa[2]<<endl;                            
}while(prev_permutation(aa,aa+3));
 
system("pause"); 
return 0;} 

 

小结：next_permutation是要在升序数组的条件下输出升序排列，prev-permutation则刚好相反
执行结果：