Submission #1035189

#	Time	Username	Problem	Language	Result	Execution time	Memory
1035189		12345678	Parachute rings (IOI12_rings)	C++17	37 / 100	998 ms	120980 KiB

rings

#include <bits/stdc++.h>

using namespace std;

const int nx=1e6+5;

int n, vs[nx], sm[nx], rem[nx], cnt, res, lvl[nx], t;
vector<int> d[nx];

void dfs(int u, int p)
{
    vs[u]=1;
    lvl[u]=lvl[p]+1;
    for (auto v:d[u])
    {
        if (v==p) continue;
        if (!vs[v]) dfs(v, u);
        else if (lvl[v]<lvl[u]) sm[u]++, rem[v]++, cnt++;
    }
}

void dfs2(int u, int p)
{
    vs[u]=1;
    for (auto v:d[u]) if (v!=p&&!vs[v]) dfs2(v, u), sm[u]+=sm[v]-rem[v];
    if (sm[u]==cnt)
    {
        int f=0, tmp=d[u].size()>2;
        for (auto v:d[u]) 
        {
            if (d[v].size()>3) f=1;
            else if (d[v].size()==3) tmp++;
        }
        if (!f&&tmp==t) res++;
    }
}

void Init(int N_) {
    n=N_;
}

void Link(int A, int B) {
    d[A].push_back(B), d[B].push_back(A);
}

int CountCritical() {
    cnt=res=t=0;
    for (int i=0; i<n; i++) vs[i]=sm[i]=rem[i]=0, t+=d[i].size()>2;
    for (int i=0; i<n; i++) if (!vs[i]) dfs(i, i);
    for (int i=0; i<n; i++) vs[i]=0;
    for (int i=0; i<n; i++) if (!vs[i]) dfs2(i, i);
    return res;
}

• Subtask 1: 20 / 20
• Subtask 2: 17 / 17
• Subtask 3: 0 / 18
• Subtask 4: 0 / 14
• Subtask 5: 0 / 31