Submission #832012

#	Time	Username	Problem	Language	Result	Execution time	Memory
832012		Antekb	Road Closures (APIO21_roads)	C++17	24 / 100	2079 ms	19508 KiB

roads

#include<bits/stdc++.h>
#include "roads.h"
#define st first
#define nd second
#define pb push_back
#define pp pop_back
#define eb emplace_back
#define mp make_pair
#define all(x) (x).begin(), (x).end()
using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<pii > vii;

void debug(){cerr<<"\n";}
template <typename H, typename... T>
void debug(H h, T... t) {cerr<<h; if (sizeof...(t)) cerr << ", "; debug(t...);}
#define deb(x...) cerr<<#x<<" = ";debug(x);

const int N=1e5+5;
vii E[N];
ll dp[N][2];

void dfs(int v, int p, int k){
	for(pii e:E[v]){
		int u=e.st, c=e.nd;
		if(u!=p){
			dfs(u, v, k);
		}
	}
	dp[v][1]=dp[v][0]=0;
		vector<int> V;
		for(pii e:E[v]){
			int u=e.st, c=e.nd;
			if(u!=p){
					dp[v][0]+=dp[u][1];
					V.pb(dp[u][0]+c-dp[u][1]);
			}
		}
		sort(all(V));
		for(int j=V.size()-1; j>=int(V.size())-k+1 && j>=0 && V[j]>0; j--){
			dp[v][0]+=V[j];
		}
		dp[v][1]=dp[v][0];
		if(V.size()>=k && V.end()[-k]>0)dp[v][1]+=V.end()[-k];
		//if(i>=2)assert(2*dp[v][1][i-1]>=dp[v][1][i]+dp[v][1][i-2]);
	//deb(v, dp[v][0], dp[v][1], dp[v][2]);
}

std::vector<long long> minimum_closure_costs(int n, std::vector<int> uu, 
	std::vector<int> vv,std::vector<int> ww) {
	ll sum=0;
	for(int i=0; i<n-1; i++){
		E[uu[i]].eb(vv[i], ww[i]);
		E[vv[i]].eb(uu[i], ww[i]);
		sum+=ww[i];
	}
	vector<ll> ans(n);
	ans[0]=sum;
	for(int i=1; i<n; i++){
		dfs(0, -1, i);
		ans[i]=sum-dp[0][1];
	}
	return ans;
}

Compilation message (stderr)

roads.cpp: In function 'void dfs(int, int, int)':
roads.cpp:28:15: warning: unused variable 'c' [-Wunused-variable]
   28 |   int u=e.st, c=e.nd;
      |               ^
roads.cpp:47:14: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   47 |   if(V.size()>=k && V.end()[-k]>0)dp[v][1]+=V.end()[-k];
      |      ~~~~~~~~^~~

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