Submission #71510

#	Time	Username	Problem	Language	Result	Execution time	Memory
71510		RezwanArefin01	Dreaming (IOI13_dreaming)	C++17	100 / 100	188 ms	21368 KiB

dreaming

#include <bits/stdc++.h>
#include "dreaming.h"
using namespace std;
 
const int N = 1e5 + 10; 
vector<int> adj[N], cost[N], R; 
int vis[N], ans, r, f[N], g[N];  
 
void dfs(int u, int par) {
    vis[u] = 1; 
    for(int i = 0; i < adj[u].size(); i++) {
        int v = adj[u][i], c = cost[u][i];
        if(v == par) continue; 
        dfs(v, u); 
        f[u] = max(f[u], f[v] + c); 
    }
}
void dfs2(int u, int par, int D) {
    int m1 = D, m2 = D;  
    for(int i = 0; i < adj[u].size(); i++) {
        int v = adj[u][i], c = cost[u][i];
        if(v == par) continue; 
        m2 = max(m2, f[v] + c);
        if(m2 > m1) swap(m1, m2); 
    } g[u] = m1;
    r = min(r, g[u]); 
    for(int i = 0; i < adj[u].size(); i++) {
        int v = adj[u][i], c = cost[u][i];
        if(v == par) continue; 
        dfs2(v, u, (f[v] + c == m1 ? m2 : m1) + c); 
    }
}
int travelTime(int N, int M, int L, int A[], int B[], int T[]) {
    for(int i = 0; i < M; i++) {
        int u = A[i], v = B[i], c = T[i]; 
        adj[u].push_back(v);
        adj[v].push_back(u);
        cost[u].push_back(c);
        cost[v].push_back(c);
    }
    for(int i = 0; i < N; i++) if(!vis[i]) {
        dfs(i, -1); r = INT_MAX;
        dfs2(i, -1, 0); 
        R.push_back(r); 
    }
    sort(R.begin(), R.end(), greater<int>());
    for(int i = 0; i < N; i++) ans = max(ans, g[i]); 
    if(R.size() > 1) ans = max(ans, R[0] + R[1] + L); 
    if(R.size() > 2) ans = max(ans, R[1] + R[2] + 2*L); 
    return ans; 
}

Compilation message (stderr)

dreaming.cpp: In function 'void dfs(int, int)':
dreaming.cpp:11:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < adj[u].size(); i++) {
                    ~~^~~~~~~~~~~~~~~
dreaming.cpp: In function 'void dfs2(int, int, int)':
dreaming.cpp:20:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < adj[u].size(); i++) {
                    ~~^~~~~~~~~~~~~~~
dreaming.cpp:27:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < adj[u].size(); i++) {
                    ~~^~~~~~~~~~~~~~~

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