Submission #1038479

#	Time	Username	Problem	Language	Result	Execution time	Memory
1038479		ArthuroWich	Dreaming (IOI13_dreaming)	C++17	47 / 100	64 ms	17648 KiB

dreaming

#include "dreaming.h"
#include<bits/stdc++.h>
using namespace std;
vector<pair<int, int>> adj[100005];
int proc[100005], no, nod, dist[100005][2];
void dfs(int i, int p, int d) {
    if (d > nod) {
        no = i, nod = d;
    }
    proc[i] = 1;
    for (auto [j, w] : adj[i]) {
        if (j == p) {
            continue;
        }
        dfs(j, i, d+w);
    }
}
void dfsdist(int i, int p, int id) {
    for (auto [j, w] : adj[i]) {
        if (j == p) {
            continue;
        }
        dist[j][id] = dist[i][id]+w;
        dfsdist(j, i, id);
    }
}
void ch(int i, int p) {
    if (max(dist[i][0], dist[i][1]) < nod) {
        no = i, nod = max(dist[i][0], dist[i][1]);
    }
    for (auto [j, _] : adj[i]) {
        if (j == p) {
            continue;
        }
        ch(j, i);
    }
}
pair<int, int> calc(int i) {
    int a, b;
    no = i, nod = 0;
    dfs(i, -1, 0);
    a = no, no = i, nod = 0;
    dfs(a, -1, 0);
    b = no;
    dfsdist(a, -1, 0);
    dfsdist(b, -1, 1);
    no = i, nod = INT_MAX;
    ch(i, -1);
    return {nod, no};
}
int travelTime(int n, int m, int l, int A[], int B[], int T[]) {
    vector<pair<int, int>> comp;
    for (int i = 0; i < m; i++) {
        adj[A[i]].push_back({B[i], T[i]});
        adj[B[i]].push_back({A[i], T[i]});
    }
    for (int i = 0; i < n; i++) {
        if (proc[i]) {
            continue;
        }
        comp.push_back(calc(i));
    }
    sort(comp.rbegin(), comp.rend());
    deque<pair<int, int>> a;
    bool f = 0;
    for (int i = 0; i < comp.size(); i += 2) {
        if (f) {
            a.push_front(comp[i]);
            if (i+1 < comp.size()) {
                a.push_back(comp[i+1]);
            }
        } else {
            a.push_back(comp[i]);
            if (i+1 < comp.size()) {
                a.push_front(comp[i+1]);
            }
        }
        f ^= 1;
    }
    for (int i = 1; i < a.size(); i++) {
        adj[a[i-1].second].push_back({a[i].second, l});
        adj[a[i].second].push_back({a[i-1].second, l});
    }
    int a1, b1;
    no = 0, nod = 0;
    for (int i = 0; i < n; i++) {
        dist[i][0] = 0;
    }
    dfs(0, -1, 0);
    a1 = no, no = 0, nod = 0;
    dfs(a1, -1, 0);
    b1 = no;
    dfsdist(a1, -1, 0);
    return dist[b1][0];
}

Compilation message (stderr)

dreaming.cpp: In function 'int travelTime(int, int, int, int*, int*, int*)':
dreaming.cpp:66:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   66 |     for (int i = 0; i < comp.size(); i += 2) {
      |                     ~~^~~~~~~~~~~~~
dreaming.cpp:69:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   69 |             if (i+1 < comp.size()) {
      |                 ~~~~^~~~~~~~~~~~~
dreaming.cpp:74:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   74 |             if (i+1 < comp.size()) {
      |                 ~~~~^~~~~~~~~~~~~
dreaming.cpp:80:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::deque<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   80 |     for (int i = 1; i < a.size(); i++) {
      |                     ~~^~~~~~~~~~

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