一.dfs形式
1.#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
int vis[20];
int a[20];
int n;
void dfs(int depth){
for(int i=1;i<=n;i++){
if(!vis[i]){
a[depth]=i;
vis[i]=1;
if(depth==n)
for(int i=1;i<=n;i++)
if(i!=n) printf("%d ",a[i]);
else printf("%d\n",a[i]);
else dfs(depth+1);
vis[i]=0;///返回原值为新排列做准备
}
}
}
int main(){
memset(vis,0,sizeof(vis));
scanf("%d",&n);
dfs(1);
return 0;
}
2.
#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
int vis[20];
int a[20];
int n;
void dfs(int depth){
if(depth==n+1){
for(int i=1;i<=n;i++){
printf("%d ",a[i]);
if(i==n) printf("\n");
}
return ;
}
for(int i=1;i<=n;i++){
if(!vis[i]){
a[depth]=i;
vis[i]=1;
dfs(depth+1);
vis[i]=0;///返回原值为新排列做准备
}
}
}
int main(){
memset(vis,0,sizeof(vis));
scanf("%d",&n);
dfs(1);
return 0;
}
二.next_permutation形式
#include<iostream>
#include<algorithm>
using namespace std;
int main(){
int a[]={1,2,3};
sort(a,a+3);
do{
cout<<a[0]<<" "<<a[1]<<" "<<a[2]<<endl;
}while(next_permutation(a,a+3));
cout<<"origal:"<<a[0]<<" "<<a[1]<<" "<<a[2]<<endl;
return 0;