제출 #1112853

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1112853		KawakiMeido	구슬과 끈 (APIO14_beads)	C++17	0 / 100	6 ms	4944 KiB

beads

/*Author: KawakiMeido*/
#include <bits/stdc++.h>
#define pb push_back
#define endl "\n"
#define ll long long
#define int long long
#define all(x) (x).begin(),(x).end()
#define pii pair<int,int>
#define fi first
#define se second

using namespace std;

/*Constants*/
const int N = 2e5+10;
const int INF = 1e9+7;
const long long LLINF = 1e15+3;

/*TestCases*/
int test=1;
void solve();
void TestCases(bool v){
    if (v) cin >> test;
    while(test--) solve();
}

/*Global Variables*/
int n;
int dp[N][2];
vector<pii> adj[N];

void DP(int u, int p, int w){
    int res = 0;
    vector<pii> tmp;
    tmp.push_back({-LLINF,0});
    tmp.push_back({-LLINF,0});
    for (auto in:adj[u]){
        int v,val; tie(v,val) = in;
        if (v==p) continue;
        DP(v,u,val);
        res+=dp[v][1];
        tmp.push_back({dp[v][0] - dp[v][1] + val,v});
    }
    sort(all(tmp),greater<pii>());
    dp[u][0] = dp[u][1] = max(res,res+tmp[0].fi+tmp[1].fi);
    dp[u][1] = max(dp[u][1],res+tmp[0].fi+w);
}

/*Solution*/
void solve(){
    cin >> n;
    for (int i=1; i<n; i++){
        int u,v,w; cin >> u >> v >> w;
        adj[u].push_back({v,w});
        adj[v].push_back({u,w});
    }
    DP(1,0,0);
    cout << dp[1][0] << endl;
}

/*Driver Code*/
signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    TestCases(0);

    return 0;
}

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