Submission #88859

#	Time	Username	Problem	Language	Result	Execution time	Memory
88859		123456	Triumphal arch (POI13_luk)	C++17	90 / 100	1900 ms	22764 KiB

luk

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;


vector<vector<int>> graph;
vector<bool> visited;


int check(int currentCity, int k) {
	int childrenSum = 0;

	visited[currentCity] = true;
	
	for (int i = 0; i < graph[currentCity].size(); i++) {
		if (!visited[graph[currentCity][i]]) {
			childrenSum += check(graph[currentCity][i], k);
		}
	}

	int numberOfChildren = graph[currentCity].size() - 1;
	if (currentCity == 0) numberOfChildren++;
	return max(0, numberOfChildren + childrenSum - k);
}

int main() {
	int numberOfTowns;
	cin >> numberOfTowns;
	if (numberOfTowns <= 1) {
		return numberOfTowns;
	}
	visited.resize(numberOfTowns);
	graph.resize(numberOfTowns);
	for (int i = 0; i < numberOfTowns - 1; i++) {
		int a, b;
		cin >> a >> b;
		a--;
		b--;

		graph[a].push_back(b);
		graph[b].push_back(a);
	}

	int start = 1;
	int end = numberOfTowns;

	int currentK;
	while (start != end) {
		for (int i = 0; i < numberOfTowns; i++) {
			visited[i] = false;	
		}
		currentK = (start + end) / 2;
		if (!check(0, currentK)) {
			end = currentK;
		}
		else {
			start = currentK + 1;
		}
	}
	cout << start << endl;
	
	return 0;
}

Compilation message (stderr)

luk.cpp: In function 'int check(int, int)':
luk.cpp:16:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < graph[currentCity].size(); i++) {
                  ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 0 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10