Submission #785013

#	Time	Username	Problem	Language	Result	Execution time	Memory
785013		zsombor	Stations (IOI20_stations)	C++17	0 / 100	635 ms	532 KiB

stations

#include <iostream>
#include <vector>
#include "stations.h"
using namespace std;

vector <vector <int>> g(1e3);
vector <int> sz(1e3, 0);
vector <int> lbl;

void dfs1(int x) {
	sz[x] = 1;
	for (int i : g[x]) {
		if (sz[i]) continue;
		dfs1(i);
		sz[x] += sz[i];
	}
}

void dfs2(int x, int l, int r, bool b) {
	if (b) { lbl[x] = l; l++; }
	else { lbl[x] = r; r--; }
	for (int i : g[x]) {
		if (lbl[i] > -1) continue;
		dfs2(i, l, l + sz[i] - 1, !b);
		l += sz[i];
	}
}

vector <int> label(int n, int k, vector <int> u, vector <int> v) {
	lbl.assign(n, -1);
	for (int i = 0; i < n - 1; i++) {
		g[u[i]].push_back(v[i]);
		g[v[i]].push_back(u[i]);
	}
	dfs1(0);
	dfs2(0, 0, n - 1, true);
	return lbl;
}

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

Compilation message (stderr)

stations.cpp: In function 'int find_next_station(int, int, std::vector<int>)':
stations.cpp:43:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   43 |   for (int i = 0; i < c.size(); i++) if (t <= c[i]) return c[i];
      |                   ~~^~~~~~~~~~
stations.cpp:47:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   47 |   for (int i = 0; i < c.size() - 1; i++) if (t <= c[i]) return c[i];
      |                   ~~^~~~~~~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 8
• Subtask 3: 0 / 16
• Subtask 4: 0 / 10
• Subtask 5: 0 / 61