Submission #968142

#	Time	Username	Problem	Language	Result	Execution time	Memory
968142		Hugo1729	Dreaming (IOI13_dreaming)	C++11	18 / 100	50 ms	12324 KiB

dreaming

#include <bits/stdc++.h>
#include "dreaming.h"
using namespace std;
#define f first
#define s second

vector<pair<int,int>> adj[100000];

int dp1[100000],dp2[100000],dp3[100000];
bool marked[100000]={0};

int dfs_sizes1(int v, int pV){
    dp1[v]=0;
    dp2[v]=0;
    marked[v]=1;
    for(auto [w,d] : adj[v]){
        if(w!=pV){
            int sus=dfs_sizes1(w,v)+d;
            if(sus>dp1[v]){
                dp2[v]=dp1[v];
                dp1[v]=sus;
            }else if(sus>dp2[v]){
                dp2[v]=sus;
            }
        }
    }
    return dp1[v];
}

void dfs_sizes2(int v, int pV){
    for(auto [w,d] : adj[v]){
        if(w!=pV){
            if(dp1[w]+d==dp1[v]){
                dp3[w]=max(dp2[v],dp3[v])+d;
            }else{
                dp3[w]=max(dp1[v],dp3[v])+d;
            }
            dfs_sizes2(w,v);
        }
    }
}

int dfs_final(int v, int pV){
    int ans=max(dp1[v],dp3[v]);

    for(auto [w,d] : adj[v]){
        if(w!=pV){
            ans=min(ans,dfs_final(w,v));
        }
    }

    return ans;
}

int travelTime(int N, int M, int L, int A[], int B[], int T[]) {
    for(int i=0;i<M;i++){
        adj[A[i]].push_back({B[i],T[i]});
        adj[B[i]].push_back({A[i],T[i]});
    }

    vector<int> sussy;

    for(int i=0;i<N;i++){
        if(!marked[i]){
            dfs_sizes1(i,i);
            dfs_sizes2(i,i);
            sussy.push_back(-dfs_final(i,i));
            // cout <<i << ' ' << sussy[sussy.size()-1] << '\n';
        }

        // cout << i << ' ' << dp1[i].first << ' ' << dp1[i].second << '\n';

    }

    for(int i=0;i<N;i++){
        // cout << i << ' ' << dp1[i] << ' ' << dp2[i] << ' ' << dp3[i] << '\n';
    }

    sort(sussy.begin(),sussy.end());

    if(sussy.size()==1)return -sussy[0];
    else if(sussy.size()==2)return -sussy[0]-sussy[1]+L;

    return max(-sussy[0]-sussy[1]+L,-sussy[2]-sussy[1]+L*2);
}

Compilation message (stderr)

dreaming.cpp: In function 'int dfs_sizes1(int, int)':
dreaming.cpp:16:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   16 |     for(auto [w,d] : adj[v]){
      |              ^
dreaming.cpp: In function 'void dfs_sizes2(int, int)':
dreaming.cpp:31:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   31 |     for(auto [w,d] : adj[v]){
      |              ^
dreaming.cpp: In function 'int dfs_final(int, int)':
dreaming.cpp:46:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   46 |     for(auto [w,d] : adj[v]){
      |              ^

• Subtask 1: 0 / 14
• Subtask 2: 0 / 10
• Subtask 3: 0 / 23
• Subtask 4: 18 / 18
• Subtask 5: 0 / 12
• Subtask 6: 0 / 23