제출 #1305264

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1305264		fly	꿈 (IOI13_dreaming)	C++20	32 / 100	32 ms	12012 KiB

dreaming

#include <bits/stdc++.h>
using namespace std;
vector<vector<pair<int, int>>> connections(100000);
vector<bool> visited(100000);
vector<pair<int, int>> far(100000, {-1, 0});
vector<pair<int, int>> sfar(100000, {-1, 0});
int treeans;
int treedia;
vector<int> answers;
vector<int> dias;
void fdfs(int cur, int par) {
    visited[cur] = true;
    for (pair<int, int> next: connections[cur]) {
        if (next.first == par) continue;
        fdfs(next.first, cur);
        int d = far[next.first].second + next.second;
        if (d > far[cur].second) {
            sfar[cur] = far[cur];
            far[cur].first = next.first;
            far[cur].second = d;
        } else if (d > sfar[cur].second) {
            sfar[cur].first = next.first;
            sfar[cur].second = d;
        }
    }
}
void sdfs(int cur, int par) {
    for (pair<int, int> next: connections[cur]) {
        if (next.first == par) continue;
        if (far[cur].first != next.first) {
            if (far[cur].second + next.second > far[next.first].second) {
                sfar[next.first] = far[next.first];
                far[next.first] = {cur, far[cur].second + next.second};
            } else if (far[cur].second + next.second > sfar[next.first].second) {
                sfar[next.first] = {cur, far[cur].second + next.second};
            }
        } else {
            if (sfar[cur].second + next.second > far[next.first].second) {
                sfar[next.first] = far[next.first];
                far[next.first] = {cur, sfar[cur].second + next.second};
            } else if (far[cur].second + next.second > sfar[next.first].second) {
                sfar[next.first] = {cur, sfar[cur].second + next.second};
            }
        }
        sdfs(next.first, cur);
    }
    treeans = min(treeans, far[cur].second);
    treedia = max(treedia, far[cur].second + sfar[cur].second);
}
extern "C"{
int travelTime(int N, int M, int L, int A[], int B[], int T[]) {
    int n = N;
    int m = M;
    int l = L;
    connections.assign(n, vector<pair<int, int>>());
    visited.assign(n, false);
    far.assign(n, {-1, 0});
    sfar.assign(n, {-1, 0});
    answers.clear();
    for (int i = 0; i < m; ++i) {
        connections[A[i]].push_back({B[i], T[i]});
        connections[B[i]].push_back({A[i], T[i]});
    }
    treedia = 0;
    for (int i = 0; i < n; ++i) {
        if (!visited[i]) {
            fdfs(i, -1);
            treeans = INT_MAX;
            sdfs(i, -1);
            answers.push_back(treeans);
            dias.push_back(treedia);
        }
    }
    sort(answers.begin(), answers.end(), greater<int>());
    if (answers.size() > 2) {
        return max(treedia, max(answers[0] + answers[1] + l, answers[1]+answers[2] + 2*l));
    }
    if (answers.size() > 1) {
        return max(treedia, answers[0] + answers[1] + l);
    } else {
        return treedia;
    }
}
}

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