제출 #802168

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
802168		borisAngelov	꿈 (IOI13_dreaming)	C++17	0 / 100	30 ms	12004 KiB

dreaming

#include "dreaming.h"
#include <bits/stdc++.h>
 
using namespace std;
 
const int maxn = 100005;
 
int n, m;
 
vector<pair<int, int>> g[maxn];
 
long long dp[maxn];
bool visited[maxn];
 
void dfs_down(int node, int par)
{
    visited[node] = true;
    dp[node] = 0;
 
    for (int i = 0; i < g[node].size(); ++i)
    {
        if (g[node][i].first != par)
        {
            dfs_down(g[node][i].first, node);
            dp[node] = max(dp[node], g[node][i].second + dp[g[node][i].first]);
        }
    }
}
 
long long dfs_up(int node, int par, long long up)
{
    long long result = max(up, dp[node]);
 
    long long max1 = 0;
    long long max2 = 0;
 
    for (int i = 0; i < g[node].size(); ++i)
    {
        int child = g[node][i].first;
        int edge = g[node][i].second;
 
        if (child == par)
        {
            continue;
        }
 
        if (dp[child] + edge > max1)
        {
            max2 = max1;
            max1 = dp[child] + edge;
        }
        else if (dp[child] + edge > max2)
        {
            max2 = dp[child] + edge;
        }
    }
 
    for (int i = 0; i < g[node].size(); ++i)
    {
        if (g[node][i].first == par)
        {
            continue;
        }
 
        int child = g[node][i].first;
        int edge = g[node][i].second;
 
        long long new_up = 0;
 
        if (dp[child] + edge == max1)
        {
            new_up = max(up, max2) + edge;
        }
        else
        {
            new_up = max(up, max1) + edge;
        }
 
        result = min(result, dfs_up(child, node, new_up));
    }
 
    return result;
}
 
int travelTime(int N, int M, int L, int A[], int B[], int T[])
{
    n = N;
    m = M;
 
    for (int i = 0; i < m; ++i)
    {
        int x = A[i] + 1;
        int y = B[i] + 1;
        int w = T[i];
 
        g[x].push_back(make_pair(y, w));
        g[y].push_back(make_pair(x, w));
    }
 
    vector<long long> dists;
 
    for (int i = 1; i <= n; ++i)
    {
        if (visited[i] == false)
        {
            dfs_down(i, -1);
            dists.push_back(dfs_up(i, -1, 0));
        }
    }
 
    sort(dists.begin(), dists.end());
 
    if (dists.size() == 1)
    {
        return dists[dists.size() - 1];
    }
 
    long long ans = dists[dists.size() - 1] + dists[dists.size() - 2] + L;
 
    if (dists.size() >= 3)
    {
        ans = max(ans, dists[dists.size() - 2] + dists[2] + 2 * L);
    }
 
    return ans;
}

컴파일 시 표준 에러 (stderr) 메시지

dreaming.cpp: In function 'void dfs_down(int, int)':
dreaming.cpp:20:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   20 |     for (int i = 0; i < g[node].size(); ++i)
      |                     ~~^~~~~~~~~~~~~~~~
dreaming.cpp: In function 'long long int dfs_up(int, int, long long int)':
dreaming.cpp:37:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   37 |     for (int i = 0; i < g[node].size(); ++i)
      |                     ~~^~~~~~~~~~~~~~~~
dreaming.cpp:58:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   58 |     for (int i = 0; i < g[node].size(); ++i)
      |                     ~~^~~~~~~~~~~~~~~~

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