Submission #89333

#	Time	Username	Problem	Language	Result	Execution time	Memory
89333		vvash17	Triumphal arch (POI13_luk)	C++14	100 / 100	1743 ms	26928 KiB

luk

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

vector<int> graph[300001];
int city_num,from,to;

int evaluate_result(int &search_start,int &need_num,int* been_there){
	int available_neigbours = 0;
	int sub_tree_res = 0;
	
	been_there[search_start]++;
	int neighbour_size = graph[search_start].size();
	for(int i = 0; i<neighbour_size; i++){
		int tmp = graph[search_start][i];
		if(been_there[tmp] == 0){
			available_neigbours++;
			sub_tree_res += evaluate_result(tmp,need_num,been_there);
		}
	}
	
	int res = available_neigbours-(need_num-sub_tree_res);
	if(res < 0)return 0;
	return res;
}
int search_init(int &need_num){
	int been_there[city_num+1] = {0};
	int start = 1;
	return evaluate_result(start,need_num,been_there);
}
int main() {
	cin>>city_num;
	for(int i = 1; i<city_num; i++){
		cin>>from>>to;
		graph[from].push_back(to);
		graph[to].push_back(from);
	}
	
	int need_num;
	int start_point = 1;
	int finish_point = city_num;
	
	int result = 0;
	
	while (start_point < finish_point) {
        need_num = (start_point+finish_point)/2;
		
		result = search_init(need_num);
		if(result == 0){
			finish_point = need_num;
		}else{
			start_point = ++need_num;
		}
		result = start_point;
    }
	cout<<result<<endl;
    return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 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