cp/codeforces/1062/2167f.cc
2025-11-03 14:33:16 -05:00

86 lines
1.6 KiB
C++

#include <algorithm>
#include <iostream>
#include <print>
#include <set>
#include <vector>
using namespace std;
using u32 = uint32_t;
using i32 = int32_t;
using u64 = uint64_t;
using i64 = int64_t;
void solve() {
u32 n;
i64 k;
cin >> n >> k;
vector<vector<u32>> tree(n + 1);
for (u32 i = 0; i < n - 1; ++i) {
u32 u, v;
cin >> u >> v;
tree[u].emplace_back(v);
tree[v].emplace_back(u);
}
u64 ans = 0;
vector<i64> size(n + 1, 0);
auto dfs = [&](auto &&self, u32 u, u32 par) -> i64 {
i64 ss = 1;
for (auto &v : tree[u]) {
if (v == par) {
continue;
}
ss += self(self, v, u);
}
return size[u] = ss;
};
dfs(dfs, 1, 0);
i64 count =
count_if(begin(size), end(size), [&k](auto const &e) { return e >= k; });
auto dfs2 = [&](auto &&self, u32 u, u32 par, i64 count) -> void {
ans += count;
for (auto v : tree[u]) {
if (v == par) {
continue;
}
auto su = size[u], sv = size[v];
size[u] = su - sv;
size[v] = n;
i64 child_count = count + (size[u] >= k) - (sv >= k);
self(self, v, u, child_count);
size[u] = su;
size[v] = sv;
}
};
dfs2(dfs2, 1, 0, count);
println("{}", ans);
}
int main() { // {{{
std::cin.exceptions(std::cin.failbit);
#ifdef LOCAL
std::cerr.rdbuf(std::cout.rdbuf());
std::cout.setf(std::ios::unitbuf);
std::cerr.setf(std::ios::unitbuf);
#else
std::cin.tie(nullptr)->sync_with_stdio(false);
#endif
u32 tc = 1;
std::cin >> tc;
for (u32 t = 0; t < tc; ++t) {
solve();
}
return 0;
}
// }}}