Submission #634230

#	Time	Username	Problem	Language	Result	Execution time	Memory
634230		Mahdi	Subtree (INOI20_subtree)	C++17	8 / 100	318 ms	1312 KiB

Main

#include<bits/stdc++.h>
using namespace std;
#define all(v) v.begin(), v.end()
#define F first
#define S second
typedef long long ll;
typedef pair<int, int> pii;
const int N=25, M=2e6;
int n, m;
bool g[N][N], a[M];

int main(){
    cin>>n>>m;
    int ans=0;
    for(int i=0;i<m;++i){
        int u, v;
        cin>>u>>v;
        g[--u][--v]=1;
        g[v][u]=1;
    }
    a[0]=1;
    for(int i=1;i<(1<<n);++i){
        int x=i;
        vector<int>w;
        for(int j=0;x;++j){
            if(x&1)
                w.push_back(j);
            x>>=1;
        }
        int t=0;
        for(int u: w){
            for(int v: w){
                if(g[u][v])
                    ++t;
            }
        }
        t/=2;
        if(t!=w.size()-1){
            continue;
        }
        for(int u: w){
            if(a[i-(1<<u)]){
                a[i]=1;
                break;
            }
        }
        if(a[i])
            ++ans;
    }
    cout<<ans<<'\n';
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:38:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   38 |         if(t!=w.size()-1){
      |            ~^~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 0 / 12
• Subtask 3: 0 / 30
• Subtask 4: 0 / 50