Submission #587686

#	Time	Username	Problem	Language	Result	Execution time	Memory
587686		M_W	Road Closures (APIO21_roads)	C++17	7 / 100	2081 ms	27380 KiB

roads

#include <bits/stdc++.h>
#define ii pair<long long, long long>
using namespace std;
vector<ii> adj[200002];

ii dfs(int a, int p, long long wt, int k){
	long long sm = 0;
	priority_queue<long long, vector<long long>, greater<long long>> pq;
	for(auto [x, w]: adj[a]){
		if(x == p) continue;
		ii res = dfs(x, a, w, k);
		sm += res.first;
		pq.push(res.second - res.first);
	}
	while(!pq.empty() && pq.top() < 0){
		sm += pq.top(); pq.pop();
	}
	while(pq.size() > k){
		sm += pq.top(); pq.pop();
	}
	ii res2 = {sm, sm + wt};
	if(a != 0 && !pq.empty() && pq.size() == k) res2.first += pq.top();
	
	return res2; 
}

vector<long long> minimum_closure_costs(int N, vector<int> U, vector<int> V, vector<int> W) {
	vector<long long> ans(N, 0);
	bool st1 = true, st2 = true;
	for(int i = 0; i < N - 1; i++){
		adj[U[i]].push_back({V[i], W[i]});
		adj[V[i]].push_back({U[i], W[i]});
		ans[0] += W[i];
		
		if(U[i]) st1 = false;
		if(U[i] + 1 != V[i]) st2 = false;
	}
	
	if(st1){
		priority_queue<long long> pq;
		for(int i = 0; i < N - 1; i++) pq.push(W[i]);
		for(int i = N - 1; i >= 0; i--){
			if(i < N - 1) ans[i] = ans[i + 1];
			if(pq.size() > i){
				ans[i] += pq.top();
				pq.pop();
			}
		}
		return ans;
	}
	
	if(st2){
		ii res = dfs(0, 0, 0, 1);
		ans[1] = res.first;
		return ans;
	}
	
	for(int i = N - 1; i > 0; i--){
		ii res = dfs(0, 0, 0, i);
		ans[i] = res.first;
	}
	
	return ans;
}

Compilation message (stderr)

roads.cpp: In function 'std::pair<long long int, long long int> dfs(int, int, long long int, int)':
roads.cpp:18:18: warning: comparison of integer expressions of different signedness: 'std::priority_queue<long long int, std::vector<long long int>, std::greater<long long int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   18 |  while(pq.size() > k){
      |        ~~~~~~~~~~^~~
roads.cpp:22:40: warning: comparison of integer expressions of different signedness: 'std::priority_queue<long long int, std::vector<long long int>, std::greater<long long int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   22 |  if(a != 0 && !pq.empty() && pq.size() == k) res2.first += pq.top();
      |                              ~~~~~~~~~~^~~~
roads.cpp: In function 'std::vector<long long int> minimum_closure_costs(int, std::vector<int>, std::vector<int>, std::vector<int>)':
roads.cpp:44:17: warning: comparison of integer expressions of different signedness: 'std::priority_queue<long long int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   44 |    if(pq.size() > i){
      |       ~~~~~~~~~~^~~

• Subtask 1: 0 / 5
• Subtask 2: 7 / 7
• Subtask 3: 0 / 14
• Subtask 4: 0 / 10
• Subtask 5: 0 / 17
• Subtask 6: 0 / 25
• Subtask 7: 0 / 22