Submission #836568

#	Time	Username	Problem	Language	Result	Execution time	Memory
836568		Liudas	City Mapping (NOI18_citymapping)	C++17	57 / 100	33 ms	528 KiB

citymapping

#include "citymapping.h"
#include <bits/stdc++.h>
using namespace std;
void find_roads(int N, int Q, int A[], int B[], int W[]) {
	vector<pair<long long, long long>> tree;
	vector<long long> init(N+5);
	int p = 0;
	for(int i = 1; i < N; i ++){
		tree.push_back({get_distance(1, i+1), i+1});
		init[i+1] = tree.back().first;
	}
	sort(tree.begin(), tree.end());
	vector<int> picks(N+20);
	vector <long long> ends;
	for(auto [j, i] : tree){
		int picked = false;
		sort(ends.begin(), ends.end(), [&](long long a, long long b){return init[a] > init[b];});
		for(auto r : ends){
			long long t = get_distance(r, i);
			if(init[i] == init[r] + t){
				picked = true;
				A[p] = i;
				B[p] = r;
				W[p++] = t;
				picks[r]++;
				ends.push_back(i);
				if(picks[r] == 2){
					ends.erase(find(ends.begin(), ends.end(), r));
				}
				break;
			}
		}
		if(!picked){
			ends.push_back(i);
			A[p] = 1;
			B[p] = i;
			W[p++] = init[i];
		}
	}
	return;
}

• Subtask 1: 9 / 9
• Subtask 2: 16 / 16
• Subtask 3: 13 / 13
• Subtask 4: 19 / 19
• Subtask 5: 0 / 43