Submission #1003234

#	Time	Username	Problem	Language	Result	Execution time	Memory
1003234		vjudge1	Subtree (INOI20_subtree)	C++17	20 / 100	778 ms	1048576 KiB

Main

#include <bits/stdc++.h>
#pragma GCC optimize("O3,unroll-loops")
  #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#define int ll
#define MAX 1000001
#define INF INT_MAX
#define MOD 1000000007
#define mp make_pair
#define mt make_tuple
#define pb push_back
#define ins insert
#define ff first
#define ss second 

#define all(a) a.begin(),a.end()
#define lb(a,b) lower_bound(all(a),b)
#define ub(a,b) upper_bound(all(a),b)
#define sortv(a) sort(all(a))
#define outputar(a,b){\
    for(int i=0;i<b;i++){\
        cout << a[i] << " ";\
    }\
    cout << endl;\
}
#define outputvec(a){\
    for(auto x:a){\
        cout << (int)x << " ";\
    }\
    cout << endl;\
}
#define reset(a,n,v){\
    for(int i=0;i<n;i++){\
        a[i]=v;\
    }\
}
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef tuple<ll,ll,ll> tll;
typedef pair<ll,ll> pll;
typedef pair<int,int> pii;
typedef double db;
typedef long double ldb;
inline void USACO(string filename){
  freopen((filename+".in").c_str(),"r",stdin);
  freopen((filename+".out").c_str(),"w",stdout);
}
int n,q,t=1,m,k,x,y,z,x2,y2,z2,a[MAX],b[MAX],d[MAX],e[MAX];
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
string s[MAX],str[MAX];
//int e[1001][1001];
string s1,s2,s3;
const int mod = 998244353;
int dx[4]={0,1,0,-1};
int dy[4]={1,0,-1,0};
vector<vector<int>> g;
int res=0;
void dfs(int v,int prev){
    a[v]=1;
    for(auto x:g[v]){
        if(x==prev){
            continue;
        }
        dfs(x,v);
        a[v]*=(a[x]+1);
        a[v]%=MOD;
    }
    res+=a[v]; 
    res%=MOD;
}
bool ok;
void dfs1(int v,int prev){
    a[v]=1;
    for(auto x:g[v]){
        if(b[x]==0 || x==prev){
            continue;
        }
        if(a[x]){
            ok=false; 
            return;
        }
        dfs1(x,v);
    }
}
void solve(){
    cin >> n >> m; 
    g.clear();
    g.resize(n);
    for(int i=0;i<m;i++){
        cin >> x >> y;
        x--; 
        y--;
        g[x].pb(y);
        g[y].pb(x); 
    }
    if(n<=20){
        int res=0;
        int h=(1<<n); 
        for(int i=1;i<h;i++){
            int h1;
            for(int j=0;j<n;j++){
                if((i&(1<<j))){
                    b[j]=1;
                    h1=j;
                }
            }
            ok=true;
            dfs1(h1,-1);
            for(int j=0;j<n;j++){
                if(b[j]==1 && a[j]==0){
                    ok=false;
                }
            }
            if(ok){
                res++;
            }
            else{
            }
            for(int j=0;j<n;j++){
                a[j]=b[j]=0;
            }

        }
        cout << res << "\n";
        return;
    }
    dfs(0,-1);
    cout << res << "\n";
}
signed main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    //freopen("input13.txt","r",stdin);
    //cin >> t;
    ll cnt1=1;
    while(t--){
        solve();
        cnt1++; 
    }
}

Compilation message (stderr)

Main.cpp: In function 'void solve()':
Main.cpp:74:19: warning: 'h1' may be used uninitialized in this function [-Wmaybe-uninitialized]
   74 |     for(auto x:g[v]){
      |                   ^
Main.cpp:100:17: note: 'h1' was declared here
  100 |             int h1;
      |                 ^~

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