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Submission #362957

# Submission time Handle Problem Language Result Execution time Memory
362957 2021-02-04T22:16:03 Z ijxjdjd Beads and wires (APIO14_beads) C++14
0 / 100
 5 ms 5100 KB 
#include <bits/stdc++.h>
#define FR(i, N) for (int i = 0; i < int(N); i++)
#define all(x) begin(x), end(x)

#define f first
#define s second
using namespace std;

using ll = long long;

const int MAXN = (int)(2e5) + 5;
vector<pair<int, int>> adj[MAXN];
int dp[MAXN][2];

void dfs(int n, int p, int w) {
    vector<int> tot;
    int allSum = 0;
    for (auto& e : adj[n]) {
        if (e.f != p) {
            dfs(e.f, n, e.s);
            tot.push_back(e.s + dp[e.f][0] - dp[e.f][1]);
            allSum += dp[e.f][1];
        }
    }
    sort(all(tot));
    reverse(all(tot));
    dp[n][0] = allSum;
    dp[n][1] = allSum;
    for (int i = 0; i < min(2, int(tot.size())); i++) {
        allSum += tot[i];
        if (i%2 == 0) {
            dp[n][1] = max(dp[n][1], allSum + w);
        }
        else {
            dp[n][0] = max(dp[n][0], allSum);
        }
    }
    dp[n][1] = max(dp[n][1], dp[n][0]);
}

int main() {
	cin.tie(0);
	cin.sync_with_stdio(0);
	int N;
	cin >> N;
	FR(i, N-1) {
        int u, v, w;
        cin >> u >> v >> w;
        u--, v--;
        adj[u].push_back({v, w});
        adj[v].push_back({u, w});
	}
	dfs(0, 0, 0);
	cout << dp[0][0] << '\n';
	return 0;
}

Subtask #1
0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 5100 KB Output is correct
2 Correct 5 ms 5100 KB Output is correct
3 Correct 4 ms 5100 KB Output is correct
4 Correct 4 ms 5100 KB Output is correct
5 Correct 4 ms 5100 KB Output is correct
6 Incorrect 4 ms 5100 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #2
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 5100 KB Output is correct
2 Correct 5 ms 5100 KB Output is correct
3 Correct 4 ms 5100 KB Output is correct
4 Correct 4 ms 5100 KB Output is correct
5 Correct 4 ms 5100 KB Output is correct
6 Incorrect 4 ms 5100 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #3
0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 5100 KB Output is correct
2 Correct 5 ms 5100 KB Output is correct
3 Correct 4 ms 5100 KB Output is correct
4 Correct 4 ms 5100 KB Output is correct
5 Correct 4 ms 5100 KB Output is correct
6 Incorrect 4 ms 5100 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #4
0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 5100 KB Output is correct
2 Correct 5 ms 5100 KB Output is correct
3 Correct 4 ms 5100 KB Output is correct
4 Correct 4 ms 5100 KB Output is correct
5 Correct 4 ms 5100 KB Output is correct
6 Incorrect 4 ms 5100 KB Output isn't correct
7 Halted 0 ms 0 KB -