题目描述

DFS指数型枚举

样例

储存结果
#include<iostream>
#include<vector>
using namespace std;
int n, m;
const int N = 25;
vector<vector<int>> ways;
int st[N];
void dfs(int u)
{   
    if(u == n)
    {
        vector<int> way;
        for(int i = 0; i < n;i ++)
            if(st[i] == 1)
                way.push_back(i + 1);
        ways.push_back(way); 
        return;     
    }
    st[u] = 2;//不选 
    dfs(u+1);
    st[u] = 0;

    st[u] = 1;//选 
    dfs(u+1);
    st[u] = 0;
}
int main()
{
    cin >> n;
    dfs(0);
    for(int i = 0; i < ways.size();i ++)
    {
        for(int j = 0; j < ways[i].size(); j++)
        {
            cout << ways[i][j] << " ";
        }
        puts("");
    }
    return 0;
 } 

#include<iostream>
#include<vector>
using namespace std;
int n, m;
const int N = 25;
int st[N];
void dfs(int u)
{   
    if(u == n)
    {
        for(int i = 0; i < n;i ++)
            if(st[i] == 1)
                cout << i+1 << " ";
        puts("");
        return;     
    }
    st[u] = 2;//不选 
    dfs(u+1);
    st[u] = 0;

    st[u] = 1;//选 
    dfs(u+1);
    st[u] = 0;
}
int main()
{
    cin >> n;
    dfs(0);

    return 0;
 }