제출 #895753

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
895753		abcvuitunggio	Flood (IOI07_flood)	C++17	60 / 100	168 ms	34336 KiB

flood

#include <bits/stdc++.h>
using namespace std;
int n,w,x[100001],y[100001],a[200001],b[200001],dx[4]={1,0,-1,0},dy[4]={0,1,0,-1},p[400001],l[100001];
vector <int> safe;
int f(int i){
    return (l[i]==i?i:l[i]=f(l[i]));
}
int main(){
    ios_base::sync_with_stdio(NULL);cin.tie(nullptr);
    cin >> n;
    vector <int> nxt[n+1][4],ve[n+1];
    vector <pair <int, int>> q[n+10];
    iota(l,l+n+1,0);
    for (int i=1;i<=n;i++)
        cin >> x[i] >> y[i];
    cin >> w;
    for (int i=1;i<=w;i++){
        cin >> a[i] >> b[i];
        l[f(a[i])]=f(b[i]);
        a[i+w]=b[i];
        b[i+w]=a[i];
        for (int j=0;j<4;j++)
            if (abs(dx[j])+abs(x[a[i]]+dx[j]-x[b[i]])==abs(x[a[i]]-x[b[i]])&&abs(dy[j])+abs(y[a[i]]+dy[j]-y[b[i]])==abs(y[a[i]]-y[b[i]])){
                nxt[a[i]][j]={i};
                nxt[b[i]][(j+2)&3]={i+w};
            }
    }
    for (int i=1;i<=n;i++)
        ve[f(i)].push_back(i);
    for (int i=1;i<=n;i++){
        if (ve[i].empty())
            continue;
        int mx=0;
        for (int j:ve[i])
            if (!mx||x[mx]>x[j]||(x[mx]==x[j]&&y[mx]<y[j]))
                mx=j;
        if (nxt[mx][3].empty())
            continue;
        q[1].push_back({nxt[mx][3][0],3});
        ve[i].clear();
    }
    for (int i=1;i<n+10;i++)
        while (!q[i].empty()){
            auto [u,d]=q[i].back();
            q[i].pop_back();
            if (p[u])
                continue;
            p[u]=i;
            q[i+1].push_back({(u>w?u-w:u+w),(d+2)&3});
            int cur=(u>w?a[u-w]:b[u]);
            for (int j=0;j<4;j++)
                if (!nxt[cur][(d+j+3)%4].empty()){
                    int v=nxt[cur][(d+j+3)%4][0];
                    nxt[cur][(d+j+3)%4].clear();
                    q[i].push_back({v,(d+j+3)%4});
                    break;
                }
        }
    for (int i=1;i<=w;i++)
        if (p[i]==p[i+w])
            safe.push_back(i);
    cout << safe.size() << '\n';
    for (int i:safe)
        cout << i << '\n';
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 0 / 10
• Subtask 4: 3 / 3
• Subtask 5: 10 / 10
• Subtask 6: 3 / 3
• Subtask 7: 0 / 3
• Subtask 8: 3 / 3
• Subtask 9: 3 / 3
• Subtask 10: 9 / 9
• Subtask 11: 9 / 9
• Subtask 12: 0 / 9
• Subtask 13: 0 / 9
• Subtask 14: 0 / 9