Submission #979303

#	Time	Username	Problem	Language	Result	Execution time	Memory
979303		Zicrus	Stations (IOI20_stations)	C++17	100 / 100	681 ms	1608 KiB

stations

#include <bits/stdc++.h>
#include "stations.h"
using namespace std;

typedef long long ll;

void dfs(vector<vector<int>> &adj, int n, int id, int prev, int &val, vector<int> &res, int layer) {
    if (!(layer & 1)) {
        res[id] += val++;
    }

    for (auto &e : adj[id]) {
        if (e == prev) continue;
        dfs(adj, n, e, id, val, res, layer + 1);
    }
    
    if (layer & 1) {
        res[id] += val++;
    }
}

vector<int> label(int n, int k, vector<int> u, vector<int> v) {
    vector<vector<int>> adj(n);
    for (ll i = 0; i < n-1; i++) {
        adj[u[i]].push_back(v[i]);
        adj[v[i]].push_back(u[i]);
    }
    vector<int> res(n, 0);
    int val = 0;
    dfs(adj, n, 0, -1, val, res, 0);
    return res;
}

int find_next_station(int s, int t, vector<int> c) {
    if (c.size() == 1) return c[0];
    if (s == 0) {
        for (ll i = 0; i <= c.size() - 1; i++) {
            if (c[i] >= t) return c[i];
        }
    }
    bool end = s > c[0];
    if (end) {
        ll parent = c[0];
        ll a = c[1];
        if (t < a || t > s) return parent;
        for (ll i = c.size() - 1; i >= 1; i--) {
            if (c[i] <= t) return c[i];
        }
    }
    else {
        ll parent = c.back();
        ll b = c[c.size() - 2];
        if (t < s || t > b) return parent;
        for (ll i = 0; i <= c.size() - 2; i++) {
            if (c[i] >= t) return c[i];
        }
    }
    return -1;
}

Compilation message (stderr)

stations.cpp: In function 'int find_next_station(int, int, std::vector<int>)':
stations.cpp:37:26: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   37 |         for (ll i = 0; i <= c.size() - 1; i++) {
      |                        ~~^~~~~~~~~~~~~~~
stations.cpp:54:26: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |         for (ll i = 0; i <= c.size() - 2; i++) {
      |                        ~~^~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 8 / 8
• Subtask 3: 16 / 16
• Subtask 4: 10 / 10
• Subtask 5: 61 / 61