/*
Mayoeba Yabureru
*/
//#include "closing.h"
#include<bits/stdc++.h>
using namespace std;
int max_score(int n, int x, int y, long long k, vector<int> U, vector<int> V, vector<int> W) {
x ++, y ++;
vector dis(n + 1, vector<long long>(2));
vector<vector<pair<int, long long>>> gr(n + 1);
for (int i = 0; i < n - 1; i ++) {
int u = U[i] + 1, v = V[i] + 1, w = W[i];
gr[u].push_back({v, w});
gr[v].push_back({u, w});
}
function<void(int, int, int)> dfs = [&] (int v, int p, int wt) {
for (auto [u, w] : gr[v]) {
if (u == p) continue;
dis[u][wt] = dis[v][wt] + w;
dfs(u, v, wt);
}
};
dfs(x, 0, 0), dfs(y, 0, 1);
multiset<pair<long long, int>> ms;
vector<int> did(n + 1);
int ans = 0;
function f = [&] {
multiset<pair<long long, int>> s;
for (int i = 1; i <= n; i ++) {
if (did[i]) continue;
s.insert({dis[i][0], i});
s.insert({dis[i][1], i});
}
int cnt = 0;
vector<int> v;
function<void(int, int, int)> go = [&] (int x, int p, int wt) {
v.push_back(x);
if (did[x] == 2) {
for (auto u : v) {
if (did[u] == 0) {
did[u] = 1;
k -= dis[u][wt];
cnt ++;
}
}
}
for (auto [u, w] : gr[x]) {
if (u == p) continue;
go(u, x, wt);
}
v.pop_back();
};
go(x, 0, 0), go(y, 0, 1);
while (s.size()) {
auto [x, y] = *s.begin();
s.erase(s.begin());
if (did[y]) continue;
if (x > k) break;
k -= x;
did[y] = 1;
cnt ++;
}
if (k >= 0) return cnt;
return -1e9;
};
long long kk = k;
ans = f();
for (int i = 1; i <= n; i ++) did[i] = 0;
int cnt = 0;
k = kk;
for (int i = 1; i <= n; i ++) ms.insert({max(dis[i][0], dis[i][1]), i});
while (ms.size()) {
vector<int> odid = did;
long long kk = k;
ans = max(ans, cnt + f());
did = odid;
k = kk;
auto [x, y] = *ms.begin();
ms.erase(ms.begin());
if (x > k) break;
k -= x;
did[y] = 2;
cnt += 2;
}
return ans;
}
/*
2
7 0 2 10
0 1 2
0 3 3
1 2 4
2 4 2
2 5 5
5 6 3
4 0 3 20
0 1 18
1 2 1
2 3 19
*/
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
int T = 1;
cin >> T;
while (T --) {
int n, x, y;
long long k;
cin >> n >> x >> y >> k;
vector<int> U(n - 1), V(n - 1), W(n - 1);
for (int i = 0; i < n - 1; i ++) cin >> U[i] >> V[i] >> W[i];
cout << max_score(n, x, y, k, U, V, W) << endl;
}
}
Compilation message
closing.cpp: In lambda function:
closing.cpp:71:16: error: inconsistent types 'int' and 'double' deduced for lambda return type
71 | return -1e9;
| ^~~~
