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QOJ
ID | 提交记录ID | 题目 | Hacker | Owner | 结果 | 提交时间 | 测评时间 |
---|---|---|---|---|---|---|---|
#402 | #164282 | #7103. Red Black Tree | y_kx_b | _Dusker | Failed. | 2023-10-04 20:22:20 | 2023-10-04 20:22:20 |
詳細信息
Extra Test:
Accepted
time: 0ms
memory: 3444kb
input:
1 9 6 1 1 3 5 6 7 9 2 1 4 3 2 8 4 3 5 5 4 3 6 4 5 7 2 8 8 5 1 9 2 1 7 2 3 4 6 7 8 9
output:
4
result:
ok single line: '4'
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 |
---|---|---|---|---|---|---|---|---|---|
#164282 | #7103. Red Black Tree | _Dusker | AC ✓ | 990ms | 29980kb | C++20 | 2.6kb | 2023-09-04 21:15:02 | 2023-09-04 21:15:02 |
answer
#include<bits/stdc++.h>
#define ioclear std::ios::sync_with_stdio(false);std::cin.tie(nullptr);std::cout.tie(nullptr);
#define endl '\n'
#define CLOCK 1e3 * clock() / CLOCKS_PER_SEC
bool mem1;
using pii = std::pair<int, int>;
using i64 = long long;
constexpr i64 inf = 0x3f3f3f3f3f3f3fll;
void solve()
{
int n, m, q;
std::cin >> n >> m >> q;
std::vector<i64> cost(n + 1, inf), dep(n + 1, 0), dep2(n + 1, 0);
for(int i = 1, x;i <= m;i++)
{
std::cin >> x;
cost[x] = 0;
}
std::vector<std::vector<pii>> edge(n + 1);
auto add = [&](int u, int v, int w)
{
edge[u].emplace_back(v, w);
};
for(int i = 1;i < n;i++)
{
int u, v, w;
std::cin >> u >> v >> w;
add(u, v, w);
add(v, u, w);
}
// const int logn = std::__lg(n);
std::vector<std::vector<int>> ancestor(n + 1, std::vector<int>(30, 0));
auto dfs = [&](auto&& self, int cur) -> void
{
for(int i = 1;(1 << i) <= dep[cur];i++)
ancestor[cur][i] = ancestor[ancestor[cur][i - 1]][i - 1];
for(auto [v, w]: edge[cur])
{
if(v == ancestor[cur][0])
continue;
ancestor[v][0] = cur;
dep[v] = dep[cur] + 1;
dep2[v] = dep2[cur] + w;
cost[v] = std::min(cost[v], cost[cur] + w);
self(self, v);
}
};
auto lca = [&](int x, int y) -> int
{
if(dep[x] < dep[y])
std::swap(x, y);
assert(dep[x] >= dep[y]);
for(int i = 20;i >= 0;i--)
if(dep[x] - (1 << i) >= dep[y])
x = ancestor[x][i];
if(x == y)
return x;
for(int i = 20;i >= 0;i--)
if(ancestor[x][i] != ancestor[y][i])
x = ancestor[x][i], y = ancestor[y][i];
return ancestor[x][0];
};
dep[1] = 1;
// ancestor[1][0] = dep[1] = 0;
dfs(dfs, 1);
for(int _ = 1;_ <= q;_++)
{
int k;
std::cin >> k;
std::vector<int> t(k);
for(auto& x: t)
std::cin >> x;
std::sort(t.begin(), t.end(), [&](int x, int y){return cost[x] < cost[y];});
int l = t.back();
i64 Ans = cost[l], maxdep = dep2[l];
// std::cout << Ans << ' ' << maxdep << endl;
for(int i = k - 1;i >= 0;i--)
{
// std::cout << t[i] << endl;
// std::cout << "beg: " << Ans << ' ' << l << ' ' << maxdep << endl;
maxdep = std::max(maxdep, dep2[t[i]]);
l = lca(l, t[i]);
Ans = std::min(Ans, std::max((i ? cost[t[i - 1]] : 0ll), maxdep - dep2[l]));
// std::cout << "end: " << Ans << ' ' << l << ' ' << maxdep << endl;
}
std::cout << Ans << endl;
}
}
bool mem2;
int main()
{
#ifdef ONLINE_JUDGE
ioclear;
#endif
int t;
std::cin >> t;
while(t--)
solve();
// std::cerr << "USED " << CLOCK << " ms\n";
// fprintf(stderr, "%.3lf MB", (&mem1 - &mem2) / 1048576.0);
}