Submission #347743

#	Time	Username	Problem	Language	Result	Execution time	Memory
347743		parsabahrami	Beads and wires (APIO14_beads)	C++17	0 / 100	4 ms	4972 KiB

beads

// Call my Name and Save me from The Dark
#include <bits/stdc++.h>
 
using namespace std;

typedef long long int ll;
typedef pair<int, int> pii;
 
#define SZ(x)                       (int) x.size()
#define F                           first
#define S                           second

const int N = 2e5 + 10;
ll dp[2][N]; int n;
vector<pair<int, ll>> adj[N];

void DFS(int v, int p = -1) {
    dp[0][v] = 0, dp[1][v] = -1e18;
    for (pair<int, ll> u : adj[v]) {
        if (u.F != p) DFS(u.F, v);
    }
    ll sum = 0;
    for (pair<int, ll> u : adj[v])
        if (u.F != p) {
            dp[0][v] = max(dp[0][v] + max(dp[0][u.F], dp[1][u.F] + u.S), dp[1][v] + dp[0][u.F] + u.S);
            dp[1][v] = max(dp[1][v] + max(dp[0][u.F], dp[1][u.F] + u.S), sum + dp[0][u.F] + u.S);
            sum += max(dp[0][u.F], dp[1][u.F] + u.S);
        }
    dp[0][v] = max(dp[0][v], sum);
    //printf("%d %d %d\n", v, dp[0][v], dp[1][v]);
}

int main() {
    scanf("%d", &n);
    for (int i = 1; i < n; i++) {
        int u, v; ll w; scanf("%d%d%lld", &u, &v, &w);
        adj[u].push_back({v, w});
        adj[v].push_back({u, w});
    }
    DFS(1);
    printf("%lld\n", dp[0][1]);
    return 0;
}

Compilation message (stderr)

beads.cpp: In function 'int main()':
beads.cpp:34:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   34 |     scanf("%d", &n);
      |     ~~~~~^~~~~~~~~~
beads.cpp:36:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   36 |         int u, v; ll w; scanf("%d%d%lld", &u, &v, &w);
      |                         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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