Submission #1305035

#	Time	Username	Problem	Language	Result	Execution time	Memory
1305035		fly	Dreaming (IOI13_dreaming)	C++20	Compilation error	0 ms	0 KiB

dreaming

#include <bits/stdc++.h>
#include dreaming.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;
vector<int> answers;
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);
}
int main() {
    freopen("dreaming.in", "r", stdin);
    freopen("dreaming.out", "w", stdout);
    int n, m, l;
    cin >> n >> m >> l;
    int a,b,t;
    for (int i = 0; i < m; ++i) {
        cin >> a >> b >> t;
        connections[a].push_back({b, t});
        connections[b].push_back({a, t});
    }
    for (int i = 0; i < n; ++i) {
        if (!visited[i]) {
            fdfs(i, -1);
            treeans = INT_MAX;
            sdfs(i, -1);
            answers.push_back(treeans);
        }
    }
    sort(answers.begin(), answers.end(), greater<int>());
    if (answers.size() > 1) {
        cout << answers[0] + answers[1] + l;
    } else {
        cout << answers[0];
    }
}

Compilation message (stderr)

dreaming.cpp:2:10: error: #include expects "FILENAME" or <FILENAME>
    2 | #include dreaming.h
      |          ^~~~~~~~
dreaming.cpp: In function 'int main()':
dreaming.cpp:49:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   49 |     freopen("dreaming.in", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
dreaming.cpp:50:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   50 |     freopen("dreaming.out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~