oj.uz

Submission #497636

# Submission time Handle Problem Language Result Execution time Memory
497636 2021-12-23T12:24:29 Z zhougz Roadside Advertisements (NOI17_roadsideadverts) C++17
100 / 100
 61 ms 10676 KB 
/**
 *    author: zhougz
 *    created: 23/12/2021 19:37:06
**/
#include <bits/stdc++.h>

using namespace std;

int n, k, cnt;
const int MAXN = 50'050, MAXK = log2(MAXN) + 1;
vector<pair<int, int>> v[MAXN];
int pre[MAXN], anc[MAXN][MAXK], dist[MAXN], dep[MAXN];

void dfs(int x, int par) {
	pre[x] = cnt++;
	anc[x][0] = par;
	for (int i = 1; i <= k; i++) {
		int half_par = anc[x][i - 1];
		if (half_par == -1) {
			break;
		}
		anc[x][i] = anc[half_par][i - 1];
	}
	for (const auto &[z, w] : v[x]) {
		if (z != par) {
			dist[z] = dist[x] + w;
			dep[z] = dep[x] + 1;
			dfs(z, x);
		}
	}
}

int lca(int a, int b) {
	if (dep[a] > dep[b]) {
		swap(a, b);
	}
	int bal = dep[b] - dep[a];
	for (int i = 0; i <= k; i++) {
		if (bal & (1 << i)) {
			b = anc[b][i];
		}
	}
	assert(dep[a] == dep[b]);
	if (a == b) {
		return a;
	}
	for (int i = k; i >= 0; i--) {
		if (anc[a][i] == anc[b][i]) {
			continue;
		}
		a = anc[a][i];
		b = anc[b][i];
	}
	assert(anc[a][0] == anc[b][0]);
	return anc[a][0];
}

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	cin >> n;
	k = log2(n);
	for (int i = 0, a, b, w; i < n - 1; i++) {
		cin >> a >> b >> w;
		v[a].emplace_back(b, w);
		v[b].emplace_back(a, w);
	}
	dfs(0, -1);
	int q;
	cin >> q;
	while (q--) {
		int arr[5];
		for (int i = 0; i < 5; i++) {
			cin >> arr[i];
		}
		sort(arr, arr + 5, [&](int a, int b) {
			return pre[a] < pre[b];
		});
		int res = 0;
		for (int i = 0; i < 5; i++) {
			res += dist[arr[i]] + dist[arr[(i + 1) % 5]] - 2 * dist[lca(arr[i], arr[(i + 1) % 5])];
		}
		cout << res / 2 << '\n';
	}
	return 0;
}

Subtask #1
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1484 KB Output is correct

Subtask #2
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 59 ms 9084 KB Output is correct
2 Correct 48 ms 10532 KB Output is correct
3 Correct 43 ms 10568 KB Output is correct
4 Correct 39 ms 10564 KB Output is correct
5 Correct 42 ms 10556 KB Output is correct
6 Correct 57 ms 10676 KB Output is correct
7 Correct 44 ms 10556 KB Output is correct
8 Correct 42 ms 10572 KB Output is correct
9 Correct 41 ms 10652 KB Output is correct
10 Correct 41 ms 10628 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 23 ms 7648 KB Output is correct
2 Correct 29 ms 10072 KB Output is correct
3 Correct 36 ms 10168 KB Output is correct
4 Correct 31 ms 10072 KB Output is correct
5 Correct 31 ms 10084 KB Output is correct
6 Correct 30 ms 10052 KB Output is correct
7 Correct 31 ms 10056 KB Output is correct
8 Correct 30 ms 10100 KB Output is correct
9 Correct 29 ms 10072 KB Output is correct
10 Correct 44 ms 10072 KB Output is correct

Subtask #4
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1484 KB Output is correct
2 Correct 59 ms 9084 KB Output is correct
3 Correct 48 ms 10532 KB Output is correct
4 Correct 43 ms 10568 KB Output is correct
5 Correct 39 ms 10564 KB Output is correct
6 Correct 42 ms 10556 KB Output is correct
7 Correct 57 ms 10676 KB Output is correct
8 Correct 44 ms 10556 KB Output is correct
9 Correct 42 ms 10572 KB Output is correct
10 Correct 41 ms 10652 KB Output is correct
11 Correct 41 ms 10628 KB Output is correct
12 Correct 23 ms 7648 KB Output is correct
13 Correct 29 ms 10072 KB Output is correct
14 Correct 36 ms 10168 KB Output is correct
15 Correct 31 ms 10072 KB Output is correct
16 Correct 31 ms 10084 KB Output is correct
17 Correct 30 ms 10052 KB Output is correct
18 Correct 31 ms 10056 KB Output is correct
19 Correct 30 ms 10100 KB Output is correct
20 Correct 29 ms 10072 KB Output is correct
21 Correct 44 ms 10072 KB Output is correct
22 Correct 39 ms 9540 KB Output is correct
23 Correct 49 ms 8240 KB Output is correct
24 Correct 43 ms 10516 KB Output is correct
25 Correct 52 ms 10472 KB Output is correct
26 Correct 39 ms 10488 KB Output is correct
27 Correct 61 ms 10444 KB Output is correct
28 Correct 42 ms 10508 KB Output is correct
29 Correct 43 ms 10480 KB Output is correct
30 Correct 44 ms 10464 KB Output is correct
31 Correct 54 ms 10472 KB Output is correct