oj.uz

답안 #634228

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
634228 2022-08-24T07:00:44 Z Mahdi Subtree (INOI20_subtree) C++17
12 / 100
 129 ms 23936 KB 
#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=1e5+5, M=1e9+7;
int n, m, dis[N], up[N], dn[N], dp[N], pd[N], a[N], b[N], c[N];
vector<int>g[N], kd[N];
bool mk[N];
pii be[N];

inline int tav(int x, int y){
    int res=1;
    while(y){
        if(y&1)
            res=1LL*res*x%M;
        x=1LL*x*x%M;
        y>>=1;
    }
    return res;
}

inline int rev(const int &x){
    return tav(x, M-2);
}

void dfs(const int &v, const int &p){
    mk[v]=1;
    be[v]={-1, -1};
    for(int u: g[v]){
        if(!mk[u]){
            dis[u]=dis[v]+1;
            kd[v].push_back(u);
            dfs(u, v);
            if(be[u].S!=-1 && up[be[u].S]!=u)
                be[v]={u, be[u].S};
        }
        else if(u!=p){
            if(dis[u]>dis[v])
                dn[v]=u;
            else
                up[v]=u;
        }
    }
    if(up[v]!=-1)
        be[p]={v, v};
}

void dfs(const int &v){
    for(int u: kd[v])
        dfs(u);
    if(dn[v]==-1){
        ll A=0, B=1;
        for(int u: kd[v]){
            A+=dp[u];
            B=B*(pd[u]+1)%M;
        }
        A+=B;
        dp[v]=A%M;
        pd[v]=B;
        if(be[v].S!=-1){
            int u=be[v].F;
            ll bc=1LL*pd[v]*rev(pd[u]+1)%M;
            a[v]=bc*(a[u]+1)%M+b[u];
            if(a[v]>=M)
                a[v]-=M;
            a[v]+=c[u];
            if(a[v]>=M)
                a[v]-=M;
            b[v]=b[u]*bc%M;
            c[v]=c[u]+b[v];
            if(c[v]>=M)
                c[v]-=M;
        }
        else if(up[v]!=-1){
            a[v]=0;
            c[v]=0;
            b[v]=pd[v];
        }
    }
    else{
        ll A=0, B=1;
        for(int u: kd[v]){
            A+=dp[u];
            if(u!=be[v].F)
                B=B*(pd[u]+1)%M;
            else
                B=B*(a[u]+1)%M;
        }
        A+=B;
        pd[v]=B;
        dp[v]=A%M;
    }
}

int main(){
    cin>>n>>m;
    for(int i=0;i<m;++i){
        int u, v;
        cin>>u>>v;
        g[--u].push_back(--v);
        g[v].push_back(u);
    }   
    memset(up, -1, sizeof(up));
    memset(dn, -1, sizeof(dn));
    dfs(0, -1);
    dfs(0);
    cout<<dp[0]<<'\n';
}

Subtask #1
0 / 8.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 5716 KB Output is correct
2 Correct 3 ms 5776 KB Output is correct
3 Correct 3 ms 5776 KB Output is correct
4 Correct 3 ms 5716 KB Output is correct
5 Correct 3 ms 5716 KB Output is correct
6 Correct 3 ms 5716 KB Output is correct
7 Correct 3 ms 5716 KB Output is correct
8 Correct 3 ms 5772 KB Output is correct
9 Correct 3 ms 5716 KB Output is correct
10 Correct 3 ms 5716 KB Output is correct
11 Correct 3 ms 5716 KB Output is correct
12 Correct 3 ms 5716 KB Output is correct
13 Incorrect 3 ms 5716 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #2
12.0 / 12.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 5776 KB Output is correct
2 Correct 10 ms 6580 KB Output is correct
3 Correct 94 ms 13832 KB Output is correct
4 Correct 94 ms 13736 KB Output is correct
5 Correct 93 ms 13840 KB Output is correct
6 Correct 98 ms 13836 KB Output is correct
7 Correct 109 ms 21656 KB Output is correct
8 Correct 109 ms 18596 KB Output is correct
9 Correct 113 ms 18000 KB Output is correct
10 Correct 74 ms 13256 KB Output is correct
11 Correct 80 ms 13808 KB Output is correct
12 Correct 105 ms 15052 KB Output is correct
13 Correct 113 ms 15180 KB Output is correct
14 Correct 90 ms 16672 KB Output is correct
15 Correct 129 ms 22852 KB Output is correct
16 Correct 128 ms 23936 KB Output is correct
17 Correct 112 ms 15184 KB Output is correct
18 Correct 125 ms 15260 KB Output is correct
19 Correct 119 ms 15348 KB Output is correct
20 Correct 72 ms 13264 KB Output is correct
21 Correct 82 ms 13128 KB Output is correct
22 Correct 93 ms 12924 KB Output is correct

Subtask #3
0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 5716 KB Output is correct
2 Correct 3 ms 5776 KB Output is correct
3 Correct 3 ms 5776 KB Output is correct
4 Correct 3 ms 5716 KB Output is correct
5 Correct 3 ms 5716 KB Output is correct
6 Correct 3 ms 5716 KB Output is correct
7 Correct 3 ms 5716 KB Output is correct
8 Correct 3 ms 5772 KB Output is correct
9 Correct 3 ms 5716 KB Output is correct
10 Correct 3 ms 5716 KB Output is correct
11 Correct 3 ms 5716 KB Output is correct
12 Correct 3 ms 5716 KB Output is correct
13 Incorrect 3 ms 5716 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #4
0 / 50.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 5716 KB Output is correct
2 Correct 3 ms 5776 KB Output is correct
3 Correct 3 ms 5776 KB Output is correct
4 Correct 3 ms 5716 KB Output is correct
5 Correct 3 ms 5716 KB Output is correct
6 Correct 3 ms 5716 KB Output is correct
7 Correct 3 ms 5716 KB Output is correct
8 Correct 3 ms 5772 KB Output is correct
9 Correct 3 ms 5716 KB Output is correct
10 Correct 3 ms 5716 KB Output is correct
11 Correct 3 ms 5716 KB Output is correct
12 Correct 3 ms 5716 KB Output is correct
13 Incorrect 3 ms 5716 KB Output isn't correct
14 Halted 0 ms 0 KB -