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답안 #977652

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
977652 2024-05-08T08:42:41 Z TranGiaHuy1508 구슬과 끈 (APIO14_beads) C++17
0 / 100
 1 ms 348 KB 
#include <bits/stdc++.h>
using namespace std;

void main_program();

signed main(){
	ios_base::sync_with_stdio(0); cin.tie(0);
	main_program();
}

using ll = long long;
using ii = pair<int, int>;

const ll inf = 1e18;

int n;
vector<vector<ii>> adj;

vector<vector<ll>> dp;

void dfs(int x, int p = -1, ll pw = -inf){
	ll best1 = -inf, best2 = -inf;
	ll sum = 0;
	for (auto [k, w]: adj[x]){
		if (k == p) continue;

		dfs(k, x, w);

		sum += dp[k][0];
		ll delta = dp[k][1] - dp[k][0];

		if (delta > best1){
			best2 = best1;
			best1 = delta;
		}
		else if (delta > best2){
			best2 = delta;
		}
	}

	sum = max(sum, 0LL);

	dp[x][0] = max({sum, sum + best1 + best2, sum + best1 + pw});
	dp[x][1] = max({sum + pw, sum + best1 + best2 + pw});
}

void main_program(){
	cin >> n;

	adj.resize(n);
	
	for (int i = 0; i < n-1; i++){
		int x, y, w; cin >> x >> y >> w;
		x--; y--;
		adj[x].emplace_back(y, w);
		adj[y].emplace_back(x, w);
	}

	dp.assign(n, {0, 0});
	dfs(0);

	cout << dp[0][0] << "\n";
}

Subtask #1
0 / 13.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 ms 344 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Incorrect 0 ms 348 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #2
0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 ms 344 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Incorrect 0 ms 348 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #3
0 / 29.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 ms 344 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Incorrect 0 ms 348 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #4
0 / 43.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 ms 344 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Incorrect 0 ms 348 KB Output isn't correct
7 Halted 0 ms 0 KB -