Submission #438879

#	Time	Username	Problem	Language	Result	Execution time	Memory
438879		keta_tsimakuridze	구슬과 끈 (APIO14_beads)	C++14	28 / 100	1085 ms	1100 KiB

beads

#include<bits/stdc++.h>
#define f first
#define s second
using namespace std;
const int N=1e4+5,mod=1e9+7;
int dp[N][2],n;
vector<pair<int,int> > V[N];
void dfs(int u,int p,int w) {
	int mx = 0;
	dp[u][0] = 0;
	for(int i=0;i<V[u].size();i++) {
		int v = V[u][i].f;
		if(v == p) continue;
		dfs(v,u,V[u][i].s);
		dp[u][0] += dp[v][1];
		mx = max(mx,-dp[v][1] + dp[v][0] + V[u][i].s + w);
	}
	dp[u][1] = dp[u][0] + mx;
}
 main(){
   ios_base::sync_with_stdio(false),cin.tie(0),cout.tie(0);
	cin>>n;
	for(int i=2;i<=n;i++){
		int u,v,w;
		cin>>u>>v>>w;
		V[u].push_back({v,w});
		V[v].push_back({u,w});
	}
	int ans = 0;
	for(int i=1;i<=n;i++) {
		dfs(i,0,0);
		ans = max(ans,dp[i][0]);
	}
	cout<<ans;
}

Compilation message (stderr)

beads.cpp: In function 'void dfs(int, int, int)':
beads.cpp:11:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   11 |  for(int i=0;i<V[u].size();i++) {
      |              ~^~~~~~~~~~~~
beads.cpp: At global scope:
beads.cpp:20:2: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   20 |  main(){
      |  ^~~~

• Subtask 1: 13 / 13
• Subtask 2: 15 / 15
• Subtask 3: 0 / 29
• Subtask 4: 0 / 43