#include <iostream>
#include <cstdio>
#include <vector>
#include <cmath>
#include <set>
#include <algorithm>
using namespace std;
using ll = long long;
const int MXN = 2e5;
vector<vector<pair<int, ll>>> adj(MXN, vector<pair<int, ll>>(0));
vector<int> dep(MXN, 0);
vector<ll> dtr(MXN, 0);
vector<set<pair<ll, int>>> tmerg(MXN);
int ans = MXN;
int k;
void dfs(int node = 0, int p = -1)
{
tmerg[node].insert({ dtr[node], dep[node] });
for (pair<int, ll> nxt : adj[node]) if (nxt.first != p)
{
dep[nxt.first] = dep[node] + 1, dtr[nxt.first] = dtr[node] + nxt.second;
dfs(nxt.first, node);
bool cont = true;
while ((!tmerg[nxt.first].empty()) && cont)
{
auto it = tmerg[nxt.first].end();
it--;
if ((*it).first - dtr[node] < k) cont = false;
else
{
if ((*it).first - dtr[node] == k) ans = fmin(ans, (*it).second - dep[node]);
tmerg[nxt.first].erase(it);
}
}
if (tmerg[node].size() < tmerg[nxt.first].size()) swap(tmerg[node], tmerg[nxt.first]);
for (pair<ll, int> tins : tmerg[nxt.first])
{
ll finddep = k - tins.first + 2 * dep[node];
auto it = tmerg[nxt.first].lower_bound({ finddep, 0 });
if ((it != tmerg[nxt.first].end()) && ((*it).first == finddep)) ans = fmin(ans, (*it).second - 2 * dep[node] + tins.second);
}
for (pair<ll, int> tins : tmerg[nxt.first])
{
auto it = tmerg[node].lower_bound(tins);
while ((it != tmerg[node].end()) && ((*it).first == tins.first))
{
tmerg[node].erase(it);
it = tmerg[node].lower_bound(tins);
}
bool ins = true;
if (it != tmerg[node].begin())
{
it--;
if ((*it).first == tins.first) ins = false;
}
if (ins) tmerg[node].insert(tins);
}
tmerg[nxt.first].clear();
}
}
int best_path(int N, int K, int H[][2], int L[])
{
k = K;
for (int i = 0; i < N - 1; i++) adj[H[i][0]].push_back({ H[i][1], L[i] }), adj[H[i][1]].push_back({ H[i][0], L[i] });
dfs();
if (ans == MXN) return -1;
else return ans;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
5 ms |
18768 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
5 ms |
18768 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
5 ms |
18768 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
5 ms |
18768 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |