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ID题目提交者结果用时内存语言文件大小提交时间测评时间
#605788#7103. Red Black Treekian2009TL 0ms12452kbC++142.1kb2024-10-02 19:37:062024-10-02 19:37:11

Judging History

你现在查看的是最新测评结果

  • [2024-10-02 19:37:11]
  • 评测
  • 测评结果:TL
  • 用时:0ms
  • 内存:12452kb
  • [2024-10-02 19:37:06]
  • 提交

answer

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;

const int MAXN = 1e5 + 10, MAXBIT = 18;

ll t, n, m, k, q, par[MAXN], near[MAXN], h[MAXN], dp[MAXN][MAXBIT], dist[MAXN][MAXBIT];
int cnt, st[MAXN], ed[MAXN];
vector<pair<int, int>> adj[MAXN];
vector<int> num;
bool red[MAXN];

void setup() {
	for (int i = 0; i < n; i++) {
		red[i] = near[i] = cnt = 0;
		adj[i].clear();
	}
}

void input() {
	cin >> n >> m >> q;
	setup();
	for (int i = 0; i < m; i++) {
		int u;
		cin >> u;
		red[--u] = true;	
	}
	for (int i = 0; i < n - 1; i++) {
		int u, v, w;
		cin >> u >> v >> w;
		adj[--u].push_back({--v, w});
		adj[v].push_back({u, w});	
	}
}

void calcDp(int u) {
	dp[u][0] = par[u];
	for (int i = 1; i < MAXBIT; i++) {
		dp[u][i] = dp[dp[u][i - 1]][i - 1];
		dist[u][i] = dist[u][i - 1] + dist[dp[u][i - 1]][i - 1];
	}
}

void dfs(int u, int p, ll d) {
	st[u] = cnt;
	cnt++;
	par[u] = p;
	if (!red[u])
		near[u] = near[p] + d;
	dist[u][0] = d;
	calcDp(u);	
	for (auto x : adj[u])
		if (x.first != p) {
			h[x.first] = h[u] + 1;
			dfs(x.first, u, x.second);
		}
	ed[u] = cnt;
	cnt++;
}

bool check(ll x) {
	int v = -1, ma = -1;
	for (auto u : num)
		if (near[u] > x) {
			ll w = u, sum = 0;
			for (int i = MAXBIT - 1; i >= 0; i--)
				if (sum + dist[w][i] <= x) {
					sum += dist[w][i];
					w = dp[w][i];
				}
			if (v == -1 || h[w] > ma) {
				v = w;
				h[w] = ma;	
			}
		}
	if (v == -1)
		return true;
	for (auto u : num)
		if (near[u] > x) {
			if (!(st[v] <= st[u] && ed[v] >= st[u]))	
				return false;
		}
	return true;
}

ll findAns() {
	ll l = -1, r = 1e14;
	while (r - l > 1) {
		ll mid = (l + r) / 2;
		if (check(mid))
			r = mid;
		else
			l = mid;
	}
	return r;
}

int main() {
	ios::sync_with_stdio(false); cin.tie(0);
	cin >> t;
	for (int i = 0; i < t; i++) {
		input();
		dfs(0, 0, 0);
		for (int j = 0; j < q; j++) {
			cin >> k;
			num.clear();
			for (int l = 0; l < k; l++) {
				int u;
				cin >> u;
				num.push_back(--u);
			}
			cout << findAns() << endl;
		}
	}
	return 0;	
}

详细

Test #1:

score: 100
Accepted
time: 0ms
memory: 12452kb

input:

2
12 2 4
1 9
1 2 1
2 3 4
3 4 3
3 5 2
2 6 2
6 7 1
6 8 2
2 9 5
9 10 2
9 11 3
1 12 10
3 3 7 8
4 4 5 7 8
4 7 8 10 11
3 4 5 12
3 2 3
1 2
1 2 1
1 3 1
1 1
2 1 2
3 1 2 3

output:

4
5
3
8
0
0
0

result:

ok 7 lines

Test #2:

score: -100
Time Limit Exceeded

input:

522
26 1 3
1
1 4 276455
18 6 49344056
18 25 58172365
19 9 12014251
2 1 15079181
17 1 50011746
8 9 2413085
23 24 23767115
22 2 26151339
26 21 50183935
17 14 16892041
9 26 53389093
1 20 62299200
24 18 56114328
11 2 50160143
6 26 14430542
16 7 32574577
3 16 59227555
3 15 8795685
4 12 5801074
5 20 57457...

output:

148616264
148616264
0
317070839
317070839
255904892
317070839
1265145897
1265145897
1072765445
538333404
455103436
285643094
285643094
285643094
317919339
0
476837157
691421476
605409472
479058444
371688030
303203698
476229270
910180170
910180170
919185207
121535083
181713164
181713164
181713164
181...

result: