Submission #341947

#	Time	Username	Problem	Language	Result	Execution time	Memory
341947		ijxjdjd	Dreaming (IOI13_dreaming)	C++14	100 / 100	103 ms	16620 KiB

dreaming

#include "dreaming.h"
#include <bits/stdc++.h>

using namespace std;
const int MAXN = (int)(1e5)+5;
vector<pair<int, int>> adj[MAXN];
int cur = -1;
int curI = -1;
pair<int, int> best;
bool visited[MAXN];
vector<pair<int, int>> total;
void furthest(int n, int p, int d) {
    visited[n] = true;
    if (d > cur) {
        cur = d;
        curI = n;
    }
    for (pair<int, int> e : adj[n]) {
        if (e.first != p) {
            furthest(e.first, n, d+e.second);
        }
    }
}
int getBest(int n, int p, int d) {
    int distTo = (n == curI ? 0 : (int)(1e9)) ;
    for (pair<int, int> e : adj[n]) {
        if (e.first != p) {
            distTo = min(distTo, getBest(e.first, n, d+e.second) + e.second);
        }
    }
    if (max(d, distTo) < best.first) {
        best = {max(d, distTo), min(d, distTo)};
    }
    return distTo;
}
void getSplit(int n) {
    cur = -1;
    furthest(n, n, 0);
    cur = -1;
    int d1 = curI;
    furthest(d1, d1, 0);
    best = {(int)(1e9), (int)(1e9)};
    getBest(d1, d1, 0);
    total.push_back(best);
}

int travelTime(int N, int M, int L, int A[], int B[], int T[]) {
    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 (!visited[i]) {
            getSplit(i);
        }
    }
    sort(total.rbegin(), total.rend());
    pair<int, int> cur = total[0];
    for (int i = 1; i < total.size(); i++) {
        if (total[i].first + L > cur.second) {
            cur = {max(total[i].first + L, cur.first), min(total[i].first+L, cur.first)};
        }
    }
    return cur.first + cur.second;
}

Compilation message (stderr)

dreaming.cpp: In function 'int travelTime(int, int, int, int*, int*, int*)':
dreaming.cpp:59:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   59 |     for (int i = 1; i < total.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