Submission #389156

#	Time	Username	Problem	Language	Result	Execution time	Memory
389156		phathnv	Beads and wires (APIO14_beads)	C++11	28 / 100	1069 ms	5580 KiB

beads

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

typedef long long ll;

const int N = 2e5 + 7;
const int INF = 1e9 + 7;

struct Edge{
    int v, c;
    Edge(int _v, int _c){
        v = _v;
        c = _c;
    }
};

int n, dp[N][2];
vector<Edge> adj[N];

void Dfs(int u, int p){
    dp[u][0] = 0;
    dp[u][1] = -INF;
    for(Edge e : adj[u]){
        int v = e.v;
        int c = e.c;
        if (v == p)
            continue;
        Dfs(v, u);
        dp[u][1] = max(dp[u][1] + max(dp[v][0], dp[v][1] + c), dp[u][0] + dp[v][0] + c);
        dp[u][0] += max(dp[v][0], dp[v][1] + c);
    }
}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    cin >> n;
    for(int i = 1; i < n; i++){
        int u, v, c;
        cin >> u >> v >> c;
        adj[u].push_back(Edge(v, c));
        adj[v].push_back(Edge(u, c));
    }

    int res = 0;
    for(int i = 1; i <= n; i++){
        Dfs(i, -1);
        res = max(res, dp[i][0]);
    }
    cout << res;

    return 0;
}

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