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ID	题目	提交者	结果	用时	内存	语言	文件大小	提交时间	测评时间
#623899	#5307. Subgraph Isomorphism	0x3fffffff	WA	58ms	3632kb	C++20	2.9kb	2024-10-09 14:20:28	2024-10-09 14:20:37

Judging History

你现在查看的是最新测评结果

[2024-10-09 14:20:37]
评测

测评结果：WA
用时：58ms
内存：3632kb

查看

[2024-10-09 14:20:28]
提交

answer

#include<bits/stdc++.h>
using namespace std;
const int N=1e5+10;

using ULL = unsigned long long;
const ULL mask = mt19937_64(chrono::steady_clock::now().time_since_epoch().count())();

ULL shift(ULL x) {
    x ^= mask;
    x ^= x << 13;
    x ^= x >> 7;
    x ^= x << 17;
    x ^= mask;
    return x;
}

void solve(){
    int n,m;cin>>n>>m;
    vector<vector<int>>e(n+1);
    vector<int>in(n+1);    
    for(int i=1;i<=m;i++){
        int a,b;cin>>a>>b;
        e[a].push_back(b);
        e[b].push_back(a);
        in[a]++;in[b]++;
    }
    if(m==n-1){
        cout<<"YES\n";return;
    }
    if(m>n){
        cout<<"NO\n";return;
    }

    queue<int>q;
    vector<int>vis(n+1);
    for(int i=1;i<=n;i++){
        if(in[i]==1){
            q.push(i);
        }
    }
    int cnt=n;
    while(not q.empty()){
        int u=q.front();
        q.pop();
        vis[u]=1;cnt--;
        for(int v:e[u]){
            if(!vis[v] and --in[v]==1){
                q.push(v);
            }
        }
    }

    int pre=0,cur=0;
    for(int i=1;i<=n;i++){
        if(!vis[i]){
            cur=i;break;
        }
    }

    vector<vector<int>>g(n+1);
    vector<int>st(n+1);

    auto dfs2=[&](auto &&ff,int u,int fa)->void{
        st[u]=1;
        for(int v:e[u]){
            if(st[v]||vis[v])continue;
            g[u].push_back(v);
            g[v].push_back(u);
            ff(ff,v,u);
        }
    };
    dfs2(dfs2,cur,0);


    vector<ULL>hase(n + 1);
    
    auto get = [&](auto&& ff, int u, int fa)->void {
        for (int v : g[u]) {
            if (v == fa)continue;
            // cout<<u<<"->"<<v<<"\n";
            ff(ff, v, u);
            hase[u] += shift(hase[v]);
        }
    };
    get(get, cur, 0);
    vector<ULL>ha(n + 1);
    ha[cur] = hase[cur];
    auto dfs1 = [&](auto&& ff, int u, int fa)->void {
        for (int v : g[u]) {
            if (v == fa)continue;
            ha[v] = hase[v] + shift(ha[u] - shift(hase[v]));
            ff(ff, v, u);
        }
    };
    dfs1(dfs1, cur, 0);//换根

    // for(int i=1;i<=n;i++){
    //     cout<<ha[i]<<"\n";
    // }
   

    vector<int>h;
    for(int i=1;i<=cnt;i++){
        h.push_back(cur);
        int now=0;
        for(int v:e[cur]){
            if(!vis[v] and v!=pre){
                now=v;break;
            }
        }
        pre=cur;
        cur=now;
    }
    for(int i=0;i+2<cnt;i++){
        int p=i+2;
        if(p>cnt)p-=cnt;
        // cout<<h[i]<<" "<<h[p]<<"\n";
        if(ha[h[i]]!=ha[h[p]]){
            cout<<"NO\n";return;
        }
    }
    cout<<"YES\n";


    // cout<<cnt<<"\n";
    // for(int i=1;i<=n;i++){
    //     cout<<vis[i]<<" ";
    // }
    // cout<<"\n";
}

signed main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    int tt=1;
    cin>>tt;
    while(tt--)
        solve();
    return 0;
}

源文件, 语言: C++20

详细

Test #1:

score: 100

Accepted

time: 1ms

memory: 3632kb

input:

output:

YES
YES
NO
YES

result:

ok 4 token(s): yes count is 3, no count is 1

Test #2:

score: -100

Wrong Answer

time: 58ms

memory: 3632kb

input:

output:

YES
YES
YES
YES
YES
YES
NO
NO
NO
YES
YES
YES
YES
NO
NO
NO
NO
YES
YES
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
NO
NO
YES
YES
NO
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
NO
NO
YES
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO...

result:

wrong answer expected NO, found YES [6th token]