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IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#668218#5437. Graph CompletingocharinWA 0ms3624kbC++202.9kb2024-10-23 12:38:342024-10-23 12:38:35

Judging History

你现在查看的是最新测评结果

  • [2024-10-23 12:38:35]
  • 评测
  • 测评结果:WA
  • 用时:0ms
  • 内存:3624kb
  • [2024-10-23 12:38:34]
  • 提交

answer

/*

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    _/_/        _/_/_/      _/    _/      _/_/_/      _/            _/       _/    _/

*/
#include<bits/stdc++.h>
#define int long long

using namespace std;
const int mod=998244353;

void solve(){
    int n,m;
    cin>>n>>m;
    vector<int>p(n+1),pp(n+1);
    auto cal=[&](int x)->int{
        return p[x%n]*pp[x/n]%mod;
    };
    p[0]=pp[0]=1;
    for(int i=1;i<=n;++i) p[i]=p[i-1]*2%mod;
    for(int i=1;i<=n;++i) pp[i]=pp[i]*p[n]%mod;
    vector<int>head(n,-1),to(2*m),nxt(2*m,-1);
    int cnt=-1;
    auto add=[&](int u,int v)->void{
        to[++cnt]=v;
        nxt[cnt]=head[u];
        head[u]=cnt;
    };
    for(int i=0;i<m;++i){
        int u,v;
        cin>>u>>v;
        --u,--v;
        add(u,v);
        add(v,u);
    }
    vector<int>dfn(n),low(n);
    int idx=0;
    stack<int>st;
    vector<int>id(n);
    auto tarjan=[&](auto tarjan,int u,int in)->void{
        dfn[u]=low[u]=++cnt;
        st.push(u);
        for(int i=head[u];~i;i=nxt[i]){
            int v=to[i];
            if(!dfn[v]){
                tarjan(tarjan,v,i^1);
                low[u]=min(low[u],low[v]);
            }
            else if(i!=in) low[u]=min(low[u],dfn[v]);
        }
        if(dfn[u]==low[u]){
            int x=st.top();st.pop();
            id[x]=idx;
            while(x!=u){
                x=st.top();st.pop();
                id[x]=idx;
            }
            idx++;
        }
    };
    tarjan(tarjan,0,-1);
    vector<int>sz(idx),c(idx);
    vector<vector<int>>e(idx);
    for(int i=0;i<n;++i){
        int u=id[i];
        sz[u]++;
        for(int j=head[i];~j;j=nxt[j]){
            int v=id[to[j]];
            if(u!=v) e[u].push_back(v);
            else c[u]++;
        }
    }
    vector f(idx,vector(n+1,0ll));
    auto dfs=[&](auto dfs,int u,int fa)->void{
        f[u][sz[u]]=cal((sz[u]-1)*sz[u]/2-c[u]/2);
        for(auto v:e[u]){
            if(v==fa) continue;
            dfs(dfs,v,u);
            vector<int>g(sz[u]+sz[v]+1,0ll);
            for(int i=0;i<=sz[u];++i){
                for(int j=0;j<=sz[v];++j){
                    g[i+j]+=f[u][i]*f[v][j]%mod*cal(i*j-1)%mod;
                    if(g[i+j]>=mod) g[i+j]-=mod;
                    g[i]+=mod-f[u][i]*f[v][j]%mod;
                    if(g[i]>=mod) g[i]-=mod;
                }
            }
        }
    };
    dfs(dfs,0,-1);
    int res=0;
    for(int i=0;i<=n;++i){
        res+=f[0][i];
        if(res>=mod) res-=mod;
    }
    cout<<res<<"\n";
}

signed main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    solve();
}

Details

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Test #1:

score: 100
Accepted
time: 0ms
memory: 3564kb

input:

3 2
1 2
2 3

output:

1

result:

ok 1 number(s): "1"

Test #2:

score: 0
Accepted
time: 0ms
memory: 3532kb

input:

4 4
1 2
2 3
3 4
4 1

output:

4

result:

ok 1 number(s): "4"

Test #3:

score: -100
Wrong Answer
time: 0ms
memory: 3624kb

input:

2 1
1 2

output:

1

result:

wrong answer 1st numbers differ - expected: '0', found: '1'