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Submission #265497

# Submission time Handle Problem Language Result Execution time Memory
265497 2020-08-14T22:24:47 Z square1001 Beads and wires (APIO14_beads) C++14
28 / 100
 1000 ms 768 KB 
#include <vector>
#include <iostream>
#include <algorithm>
#include <functional>
using namespace std;
const long long inf = 1LL << 40;
int main() {
	// step #1. read input
	cin.tie(0);
	ios_base::sync_with_stdio(false);
	int N;
	cin >> N;
	vector<int> ga(N - 1), gb(N - 1); vector<long long> gw(N - 1);
	for(int i = 0; i < N - 1; ++i) {
		cin >> ga[i] >> gb[i] >> gw[i];
		--ga[i], --gb[i];
	}
	// step #2. construct a graph
	vector<int> sep(N + 1);
	for(int i = 0; i < N - 1; ++i) {
		++sep[ga[i] + 1];
		++sep[gb[i] + 1];
	}
	for(int i = 0; i < N; ++i) {
		sep[i + 1] += sep[i];
	}
	vector<int> ctr(sep);
	vector<int> to(2 * N - 2); vector<long long> cost(2 * N - 2);
	for(int i = 0; i < N - 1; ++i) {
		to[ctr[ga[i]]] = gb[i]; cost[ctr[ga[i]]++] = gw[i];
		to[ctr[gb[i]]] = ga[i]; cost[ctr[gb[i]]++] = gw[i];
	}
	// step #3. calculation
	function<pair<long long, long long>(int, int)> solve = [&](int pos, int pre) {
		// returns = (no mid-blue, one mid-blue)
		long long sumcost = 0, delta = -inf;
		for(int i = sep[pos]; i < sep[pos + 1]; ++i) {
			if(to[i] == pre) continue;
			pair<long long, long long> res = solve(to[i], pos);
			sumcost += max(res.first, res.second + cost[i]);
			delta = max(delta, cost[i] - max(res.second + cost[i] - res.first, 0LL));
		}
		return make_pair(sumcost, sumcost + delta);
	};
	long long ans = 0;
	for(int i = 0; i < N; ++i) {
		pair<long long, long long> res = solve(i, -1);
		ans = max(ans, res.first);
	}
	// step #4. print the answer
	cout << ans << endl;
	return 0;
}

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 384 KB Output is correct
2 Correct 1 ms 384 KB Output is correct
3 Correct 0 ms 384 KB Output is correct
4 Correct 1 ms 384 KB Output is correct
5 Correct 0 ms 384 KB Output is correct
6 Correct 0 ms 384 KB Output is correct
7 Correct 0 ms 384 KB Output is correct
8 Correct 1 ms 384 KB Output is correct
9 Correct 0 ms 384 KB Output is correct
10 Correct 0 ms 384 KB Output is correct
11 Correct 1 ms 384 KB Output is correct
12 Correct 1 ms 384 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 384 KB Output is correct
2 Correct 1 ms 384 KB Output is correct
3 Correct 0 ms 384 KB Output is correct
4 Correct 1 ms 384 KB Output is correct
5 Correct 0 ms 384 KB Output is correct
6 Correct 0 ms 384 KB Output is correct
7 Correct 0 ms 384 KB Output is correct
8 Correct 1 ms 384 KB Output is correct
9 Correct 0 ms 384 KB Output is correct
10 Correct 0 ms 384 KB Output is correct
11 Correct 1 ms 384 KB Output is correct
12 Correct 1 ms 384 KB Output is correct
13 Correct 1 ms 384 KB Output is correct
14 Correct 1 ms 384 KB Output is correct
15 Correct 1 ms 384 KB Output is correct
16 Correct 1 ms 384 KB Output is correct
17 Correct 1 ms 384 KB Output is correct
18 Correct 1 ms 384 KB Output is correct
19 Correct 1 ms 512 KB Output is correct
20 Correct 1 ms 384 KB Output is correct
21 Correct 2 ms 384 KB Output is correct
22 Correct 1 ms 384 KB Output is correct

Subtask #3
0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 384 KB Output is correct
2 Correct 1 ms 384 KB Output is correct
3 Correct 0 ms 384 KB Output is correct
4 Correct 1 ms 384 KB Output is correct
5 Correct 0 ms 384 KB Output is correct
6 Correct 0 ms 384 KB Output is correct
7 Correct 0 ms 384 KB Output is correct
8 Correct 1 ms 384 KB Output is correct
9 Correct 0 ms 384 KB Output is correct
10 Correct 0 ms 384 KB Output is correct
11 Correct 1 ms 384 KB Output is correct
12 Correct 1 ms 384 KB Output is correct
13 Correct 1 ms 384 KB Output is correct
14 Correct 1 ms 384 KB Output is correct
15 Correct 1 ms 384 KB Output is correct
16 Correct 1 ms 384 KB Output is correct
17 Correct 1 ms 384 KB Output is correct
18 Correct 1 ms 384 KB Output is correct
19 Correct 1 ms 512 KB Output is correct
20 Correct 1 ms 384 KB Output is correct
21 Correct 2 ms 384 KB Output is correct
22 Correct 1 ms 384 KB Output is correct
23 Correct 611 ms 748 KB Output is correct
24 Correct 602 ms 624 KB Output is correct
25 Correct 603 ms 632 KB Output is correct
26 Execution timed out 1050 ms 768 KB Time limit exceeded
27 Halted 0 ms 0 KB -

Subtask #4
0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 384 KB Output is correct
2 Correct 1 ms 384 KB Output is correct
3 Correct 0 ms 384 KB Output is correct
4 Correct 1 ms 384 KB Output is correct
5 Correct 0 ms 384 KB Output is correct
6 Correct 0 ms 384 KB Output is correct
7 Correct 0 ms 384 KB Output is correct
8 Correct 1 ms 384 KB Output is correct
9 Correct 0 ms 384 KB Output is correct
10 Correct 0 ms 384 KB Output is correct
11 Correct 1 ms 384 KB Output is correct
12 Correct 1 ms 384 KB Output is correct
13 Correct 1 ms 384 KB Output is correct
14 Correct 1 ms 384 KB Output is correct
15 Correct 1 ms 384 KB Output is correct
16 Correct 1 ms 384 KB Output is correct
17 Correct 1 ms 384 KB Output is correct
18 Correct 1 ms 384 KB Output is correct
19 Correct 1 ms 512 KB Output is correct
20 Correct 1 ms 384 KB Output is correct
21 Correct 2 ms 384 KB Output is correct
22 Correct 1 ms 384 KB Output is correct
23 Correct 611 ms 748 KB Output is correct
24 Correct 602 ms 624 KB Output is correct
25 Correct 603 ms 632 KB Output is correct
26 Execution timed out 1050 ms 768 KB Time limit exceeded
27 Halted 0 ms 0 KB -