Submission #557391

#	Time	Username	Problem	Language	Result	Execution time	Memory
557391		Jarif_Rahman	Dreaming (IOI13_dreaming)	C++17	100 / 100	80 ms	16668 KiB

dreaming

#include "dreaming.h"
#include <bits/stdc++.h>
#define pb push_back
#define f first
#define sc second
using namespace std;
typedef long long int ll;
typedef string str;

int ans = 0;
vector<vector<pair<int, int>>> v;
vector<bool> bl;
vector<int> dis;

void dfs1(int nd, int ss){
    bl[nd] = 1;
    for(auto [x, w]: v[nd]) if(x != ss) dfs1(x, nd);
    for(auto [x, w]: v[nd]) if(x != ss) dis[nd] = max(dis[nd], dis[x]+w);
}
int dfs2(int nd, int ss, int s = 0){
    int mx = s, smx = s;
    int rt = s;
    for(auto [x, w]: v[nd]) if(x != ss){
        rt = max(rt, dis[x]+w);
        if(dis[x]+w > mx) smx = mx, mx = dis[x]+w;
        else if(dis[x]+w > smx) smx = dis[x]+w;
    }
    ans = max(ans, rt);
    for(auto [x, w]: v[nd]) if(x != ss) rt = min(rt, dfs2(x, nd, (dis[x]+w == mx?smx:mx)+w));
    return rt;
}

int travelTime(int n, int m, int L, int A[], int B[], int T[]){
    v.assign(n, {});
    bl.assign(n, 0);
    dis.assign(n, 0);

    for(int i = 0; i < m; i++){
        v[A[i]].pb({B[i], T[i]});
        v[B[i]].pb({A[i], T[i]});
    }

    vector<int> sth;

    for(int i = 0; i < n; i++){
        if(bl[i]) continue;
        dfs1(i, -1);
        sth.pb(dfs2(i, -1));
    }

    sort(sth.rbegin(), sth.rend());

    if(sth.size() == 1) return ans;

    ans = max(ans, sth[0]+sth[1]+L);
    if(sth.size() > 2) ans = max(ans, sth[1]+sth[2]+2*L);

    return ans;
}

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