Submission #1280571

#	Time	Username	Problem	Language	Result	Execution time	Memory
1280571		coderg300711	Flood (IOI07_flood)	C++20	0 / 100	160 ms	25920 KiB

flood

#include <bits/stdc++.h>
using namespace std;

const int N=100100;

int X[N],Y[N],lev[N*4],side[N][4][2],vals[4*N];
bitset<4*N> vis;
vector<int> adj[4*N];

void AE(int a,int b){
    adj[a].push_back(b);
    adj[b].push_back(a);
}

set<pair<int,int>> st;

signed main(){
    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);

    int n,w;
    cin>>n;
    for(int i=1;i<=n;i++)cin>>X[i]>>Y[i];
    cin>>w;
    for(int i=1;i<=w;i++){
        int a,b;
        cin>>a>>b;
        if(X[a]==X[b]){
            if(Y[a]>Y[b])swap(a,b);
            side[a][2][1]=i;
            side[a][2][0]=i+w;
            side[b][0][0]=i;
            side[b][0][1]=i+w;
            vals[i]=X[a];
            st.insert({vals[i],i});
        }else{
            if(X[a]>X[b])swap(a,b);
            side[a][1][0]=i;
            side[a][1][1]=i+w;
            side[b][3][1]=i;
            side[b][3][0]=i+w;
            vals[i]=1e9;
        }
    }
    for(int i=1;i<=n;i++)
        for(int j=0;j<4;j++)if(side[i][j][0])
            for(int k=(j+1)%4;;k=(k+1)%4)
               if(side[i][k][0]){
                AE(side[i][k][0],side[i][j][1]);
                break;
            }

    deque<int> Q;
    memset(lev,7,sizeof lev);
    while(1){
        if(st.empty())break;
        int K=st.begin()->second;
        Q.push_back(K);
        lev[K]=0;
        while(Q.size()){
            int x=Q.front();
            Q.pop_front();
            if(vis[x])continue;
            if(x<=w)st.erase({vals[x],x});
            vis[x]=1;
            for(auto y:adj[x])
            if(lev[y]<lev[x])Q.push_front(y),lev[y]=lev[x];
            adj[x].clear();
            int k=(x>w?x-w:x+w);
            if(lev[k]>lev[x]+1)lev[k]=lev[x]+1,Q.push_back(k);
        }
    }
    vector<int> a;
    for(int i=1;i<=w;i++){
        if(lev[i]==lev[i+w])a.push_back(i);
    }
    cout<<a.size()<<'\n';
    for(auto x:a)cout<<x<<'\n';
}

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