Submission #852382

#	Time	Username	Problem	Language	Result	Execution time	Memory
852382		abcvuitunggio	Tropical Garden (IOI11_garden)	C++17	100 / 100	4035 ms	30184 KiB

garden

#include "garden.h"
#include "gardenlib.h"
#include <bits/stdc++.h>
using namespace std;
int mx[150001],mx2[150001],nxt[300001],ch[300001],id,cycle[300001],d[300001],res,idx[300001],pos[300001];
vector <int> ke[300001],ve[300001],tmp;
void dfs(int u){
    for (int v:ke[u]){
        d[v]=d[u]+1;
        dfs(v);
    }
}
void dfs2(int u, int val){
    if (u%2==0&&d[u]==val){
        ch[u]=1;
        return;
    }
    for (int v:ke[u])
        dfs2(v,val);
}
void count_routes(int N, int M, int P, int R[][2], int Q, int G[]){
    memset(mx,-1,sizeof(mx));
    memset(mx2,-1,sizeof(mx2));
    reverse(R,R+M);
    for (int i=0;i<M;i++){
        int u=R[i][0],v=R[i][1];
        if (mx[u]<i){
            mx2[u]=mx[u];
            mx[u]=i;
        }
        else if (mx2[u]<i)
            mx2[u]=i;
        if (mx[v]<i){
            mx2[v]=mx[v];
            mx[v]=i;
        }
        else if (mx2[v]<i)
            mx2[v]=i;
    }
    for (int i=0;i<N;i++){
        int v=R[mx[i]][0]^R[mx[i]][1]^i;
        nxt[i*2]=v*2+1-(mx[i]!=mx[v]||mx2[v]==-1);
        if (mx2[i]==-1)
            continue;
        v=R[mx2[i]][0]^R[mx2[i]][1]^i;
        nxt[i*2+1]=v*2+1-(mx2[i]!=mx[v]||mx2[v]==-1);
    }
    for (int i=0;i<N*2;i++){
        if (!ch[i]){
            tmp.clear();
            tmp.push_back(i);
            int u=i;
            while (true){
                u=nxt[u];
                if (ch[u]>1){
                    for (int j:tmp){
                        idx[j]=idx[u];
                        pos[j]=pos[u];
                        ch[j]=2;
                    }
                    break;
                }
                if (ch[u]==1){
                    int p=0;
                    for (int j=0;j<tmp.size();j++)
                        if (tmp[j]==u)
                            p=j;
                    for (int j=p;j<tmp.size();j++){
                        ve[id].push_back(tmp[j]);
                        cycle[tmp[j]]=1;
                        pos[tmp[j]]=j-p;
                    }
                    for (int j:tmp){
                        idx[j]=id;
                        ch[j]=2;
                    }
                    id++;
                    break;
                }
                tmp.push_back(u);
                ch[u]=1;
            }
        }
    }
    for (int i=0;i<N*2;i++)
        if (!cycle[i])
            ke[nxt[i]].push_back(i);
    for (int i=0;i<id;i++)
        for (int j:ve[i])
            dfs(j);
    memset(ch,0,sizeof(ch));
    for (int i=0;i<Q;i++){
        res=0;
        dfs2(P*2,d[P*2]+G[i]);
        dfs2(P*2+1,d[P*2+1]+G[i]);
        for (int j=0;j<N*2;j+=2){
            if (!ch[j]&&d[j]<G[i]){
                int v=ve[idx[j]][(pos[j]+G[i]-d[j])%ve[idx[j]].size()];
                ch[j]=(v==P*2||v==P*2+1);
            }
            res+=ch[j];
            ch[j]=0;
        }
        answer(res);
    }
}

Compilation message (stderr)

garden.cpp: In function 'void count_routes(int, int, int, int (*)[2], int, int*)':
garden.cpp:65:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   65 |                     for (int j=0;j<tmp.size();j++)
      |                                  ~^~~~~~~~~~~
garden.cpp:68:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   68 |                     for (int j=p;j<tmp.size();j++){
      |                                  ~^~~~~~~~~~~

• Subtask 1: 49 / 49
• Subtask 2: 20 / 20
• Subtask 3: 31 / 31