Submission #563947

#	Time	Username	Problem	Language	Result	Execution time	Memory
563947		minhcool	Road Closures (APIO21_roads)	C++17	0 / 100	52 ms	18192 KiB

roads

#include "roads.h"
#include<bits/stdc++.h>
using namespace std;

//#define int long long
#define fi first
#define se second
#define pb push_back

typedef pair<int, int> ii;
typedef pair<ii, int> iii;
typedef pair<ii, ii> iiii;

const int N = 1e5 + 5, oo = 1e18 + 7, mod = 1e9 + 7;

int n;

vector<ii> Adj[N];

int k;
int dp[N][2];

void dfs(int u, int p){
	int we;
	for(auto it : Adj[u]){
		int v = it.fi;
		if(v == p){
			we = it.se;
			continue;
		}
		dfs(v, u);
	}
	vector<int> vc;
	int sum = 0;
	for(auto it : Adj[u]){
		int v = it.fi;
		if(v == p) continue;
		sum += dp[v][0];
		vc.pb(dp[v][0] - dp[v][1]);
	}
	sort(vc.begin(), vc.end());
	reverse(vc.begin(), vc.end());
	int sum2 = 0;
	for(int i = 0; i < min((int)Adj[u].size(), k - 1); i++){
		sum2 += max(0, vc[i]);
	}
	dp[u][0] = sum - sum2 - ((Adj[u].size() < k) ? 0 : max(0, vc[k - 1])) + we;
	dp[u][1] = sum - sum2;
}

vector<long long> minimum_closure_costs(int N, vector<int> U, vector<int> V, vector<int> W){
	n = N;
	for(int i = 0; i < (n - 1); i++){
		Adj[U[i]].pb({V[i], W[i]});
		Adj[V[i]].pb({U[i], W[i]});
	}
	vector<long long> ans;
	for(int i = 0; i < n; i++){
		k = i;
		dfs(1, 1);
		ans.pb(min(dp[i][0], dp[i][1]));		
	}
	return ans;
}

Compilation message (stderr)

roads.cpp:14:34: warning: overflow in conversion from 'double' to 'int' changes value from '1.0e+18' to '2147483647' [-Woverflow]
   14 | const int N = 1e5 + 5, oo = 1e18 + 7, mod = 1e9 + 7;
      |                             ~~~~~^~~
roads.cpp: In function 'void dfs(int, int)':
roads.cpp:47:42: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   47 |  dp[u][0] = sum - sum2 - ((Adj[u].size() < k) ? 0 : max(0, vc[k - 1])) + we;
      |                            ~~~~~~~~~~~~~~^~~
roads.cpp:47:72: warning: 'we' may be used uninitialized in this function [-Wmaybe-uninitialized]
   47 |  dp[u][0] = sum - sum2 - ((Adj[u].size() < k) ? 0 : max(0, vc[k - 1])) + we;
      |             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~

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