對數組{1,2,3}進行全排列
#include <iostream>
using namespace std;
void swap(int a[],int i,int j)
{
int tmp = a[i];
a[i] = a[j];
a[j] = tmp;
}
void printArray(int a[],int n)
{
for(int i=0; i<n; i++)
cout<<a[i]<<" ";
cout<<endl;
}
void perm(int a[],int p,int q)
{
if(p==q)
printArray(a,q+1);
for(int i=p; i<=q; i++)
{
swap(a,p,i);
perm(a,p+1,q);
swap(a,p,i);
}
}
int main()
{
int a[] = {1,2,3};
perm(a,0,2);
return 0;
}
STL next_permutation
#include <algorithm>
int main()
{
int a[] = {1,2,3};
//perm(a,0,2);
do
{
for(int i=0;i<3;i++)
cout<<a[i]<<" ";
cout<<endl;
}while(next_permutation(a,a+3));
return 0;
}
