Submission #670138

#	Time	Username	Problem	Language	Result	Execution time	Memory
670138		Mahdi	Beads and wires (APIO14_beads)	C++17	0 / 100	3 ms	4948 KiB

beads

#include<bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;
#define all(v) v.begin(), v.end()
#define F first
#define S second
typedef long long ll;
typedef pair<int, int> pii;
const int N=2e5+5;
int n, dp[N], pd[N], py[N];
vector<pii>g[N];

void dfs(const int &v, const int &p=-1){
    for(pii u: g[v]){
        if(u.F!=p){
            py[u.F]=u.S;
            dfs(u.F, v);
            pd[v]+=dp[u.F];
        }
    }
    int x=0, y=-2e9, z=0;
    for(pii u: g[v]){
        if(u.F!=p){
            z=max(z+dp[u.F], y+pd[u.F]+u.S);
            y=max(y+dp[u.F], x+pd[u.F]+u.S);
            x+=dp[u.F];
        }
    }
    pd[v]=max(pd[v], z);
    dp[v]=max(pd[v], y+py[v]);
}

int main(){
    cin>>n;
    for(int i=1;i<n;++i){
        int u, v, w;
        cin>>u>>v>>w;
        g[--u].push_back({--v, w});
        g[v].push_back({u, w});
    }
    py[0]=-2e9;
    dfs(0);
    cout<<dp[0]<<'\n';
}

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