#include <bits/stdc++.h>
using namespace std;
using ld = long double;
using ull = unsigned long long;
/*
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("-O3")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
*/
template <class T> inline T gcd(T a , T b) { return !a ? b : gcd(b % a , a); }
template <class T> inline T lcm(T a , T b) {return (a * b) / gcd(a , b) ; }
mt19937 rnd(time(0));
#define all(x) x.begin(), x.end()
#define debug(x) { cerr << #x << " = " << x << endl; }
const int N = 1e5 + 2;
int n, k, sub[N], depth[N];
long long fen[N], ans = 0ll;
vector<bool> used(N, false);
vector<pair<int, int>> cnt;
vector<vector<pair<int, int>>> g(N, vector<pair<int, int>>());
void calc(int v, int par = -1) {
sub[v] = 1;
if (par != -1) {
depth[v] = depth[par] + 1;
} else {
depth[v] = 0;
}
for (auto edge : g[v]) {
int to = edge.first;
if (to != par && !used[to]) {
calc(to, v);
sub[v] += sub[to];
}
}
return;
}
int getCentroid(int v, int par, int subSize) {
for (auto edge : g[v]) {
int to = edge.first;
if (sub[to] > (subSize / 2) && !used[to] && to != par) {
return getCentroid(to, v, subSize);
}
}
return v;
}
void dfs1(int v, int par, int maxEdge) {
cnt.push_back({v, maxEdge});
for (auto edge : g[v]) {
int to = edge.first, wei = edge.second;
if (!used[to] && to != par) {
dfs1(to, v, max(maxEdge, wei));
}
}
return;
}
bool comp(const pair<int, int> &p1, const pair<int, int> &p2) {
if (p1.second != p2.second) {
return p1.second < p2.second;
}
return p1.first < p2.first;
}
long long query(int R) {
long long sum = 0ll;
R++;
for (; R >= 0; R = (R & (R + 1)) - 1) {
sum += fen[R];
}
return sum;
}
void upd(int i, long long value) {
i++;
for (; i < N - 1; i = (i | (i + 1))) {
fen[i] += value;
}
return;
}
void decompose(int v) {
calc(v);
used[v] = true;
dfs1(v, -1, 0);
sort(all(cnt), comp);
for (auto temp : cnt) {
int ver = temp.first, wei = temp.second;
ans += query(wei - k - depth[ver]);
upd(depth[ver], +1);
}
for (auto temp : cnt) {
int ver = temp.first;
upd(depth[ver], -1);
}
cnt.clear();
for (auto edge : g[v]) {
int to = edge.first;
if (!used[to]) {
dfs1(to, v, edge.second);
sort(all(cnt), comp);
for (auto temp : cnt) {
int ver = temp.first, wei = temp.second;
ans -= query(wei - k - depth[ver]);
upd(depth[ver], +1);
}
for (auto temp : cnt) {
int ver = temp.first;
upd(depth[ver], -1);
}
cnt.clear();
}
}
for (auto edge : g[v]) {
int to = edge.first;
if (!used[to]) {
decompose(to);
}
}
return;
}
void solve() {
cin >> n >> k;
for (int i = 1; i < n; i++) {
int u, v, wei;
cin >> u >> v >> wei;
g[u].push_back({v, wei});
g[v].push_back({u, wei});
}
decompose(getCentroid(1, -1, n));
cout << 2ll * ans << '\n';
return;
}
signed main() {
ios_base :: sync_with_stdio(0);
cin.tie(0) , cout.tie(0);
int t = 1;
while (t-- > 0) {
solve();
}
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
2796 KB |
Output is correct |
2 |
Correct |
2 ms |
2796 KB |
Output is correct |
3 |
Correct |
3 ms |
2796 KB |
Output is correct |
4 |
Correct |
122 ms |
3052 KB |
Output is correct |
5 |
Correct |
116 ms |
2924 KB |
Output is correct |
6 |
Correct |
129 ms |
2924 KB |
Output is correct |
7 |
Correct |
115 ms |
2924 KB |
Output is correct |
8 |
Correct |
123 ms |
2924 KB |
Output is correct |
9 |
Correct |
3 ms |
2796 KB |
Output is correct |
10 |
Correct |
3 ms |
2796 KB |
Output is correct |
11 |
Correct |
3 ms |
2796 KB |
Output is correct |
12 |
Correct |
10 ms |
2796 KB |
Output is correct |
13 |
Correct |
10 ms |
2796 KB |
Output is correct |
14 |
Correct |
11 ms |
2796 KB |
Output is correct |
15 |
Correct |
4 ms |
2796 KB |
Output is correct |
16 |
Correct |
5 ms |
2796 KB |
Output is correct |
17 |
Correct |
4 ms |
2796 KB |
Output is correct |
18 |
Correct |
4 ms |
2796 KB |
Output is correct |
19 |
Correct |
4 ms |
2796 KB |
Output is correct |
20 |
Correct |
4 ms |
2796 KB |
Output is correct |
21 |
Correct |
5 ms |
2796 KB |
Output is correct |
22 |
Correct |
4 ms |
2796 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
2796 KB |
Output is correct |
2 |
Correct |
2 ms |
2796 KB |
Output is correct |
3 |
Correct |
3 ms |
2816 KB |
Output is correct |
4 |
Correct |
122 ms |
2924 KB |
Output is correct |
5 |
Execution timed out |
1548 ms |
4372 KB |
Time limit exceeded |
6 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
2796 KB |
Output is correct |
2 |
Correct |
2 ms |
2796 KB |
Output is correct |
3 |
Correct |
3 ms |
2796 KB |
Output is correct |
4 |
Correct |
122 ms |
3052 KB |
Output is correct |
5 |
Correct |
116 ms |
2924 KB |
Output is correct |
6 |
Correct |
129 ms |
2924 KB |
Output is correct |
7 |
Correct |
115 ms |
2924 KB |
Output is correct |
8 |
Correct |
123 ms |
2924 KB |
Output is correct |
9 |
Correct |
3 ms |
2796 KB |
Output is correct |
10 |
Correct |
3 ms |
2796 KB |
Output is correct |
11 |
Correct |
3 ms |
2796 KB |
Output is correct |
12 |
Correct |
10 ms |
2796 KB |
Output is correct |
13 |
Correct |
10 ms |
2796 KB |
Output is correct |
14 |
Correct |
11 ms |
2796 KB |
Output is correct |
15 |
Correct |
4 ms |
2796 KB |
Output is correct |
16 |
Correct |
5 ms |
2796 KB |
Output is correct |
17 |
Correct |
4 ms |
2796 KB |
Output is correct |
18 |
Correct |
4 ms |
2796 KB |
Output is correct |
19 |
Correct |
4 ms |
2796 KB |
Output is correct |
20 |
Correct |
4 ms |
2796 KB |
Output is correct |
21 |
Correct |
5 ms |
2796 KB |
Output is correct |
22 |
Correct |
4 ms |
2796 KB |
Output is correct |
23 |
Correct |
2 ms |
2796 KB |
Output is correct |
24 |
Correct |
2 ms |
2796 KB |
Output is correct |
25 |
Correct |
3 ms |
2816 KB |
Output is correct |
26 |
Correct |
122 ms |
2924 KB |
Output is correct |
27 |
Execution timed out |
1548 ms |
4372 KB |
Time limit exceeded |
28 |
Halted |
0 ms |
0 KB |
- |