#include <bits/stdc++.h>
using namespace std;
typedef double db;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
#define lx (id << 1)
#define rx (lx | 1)
#define gcd __gcd
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define bit(i, mask) ((mask) >> (i) & 1)
#define reset(x, val) memset(x, val, sizeof(x))
#define foru(i,a,b) for(int i = (a); i <= (b); ++i)
#define ford(i,a,b) for(int i = (a); i >= (b); --i)
#define FastIO ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
template<typename T> bool maximize(T &res, const T &val) { if (res < val) { res = val; return true; } return false; }
template<typename T> bool minimize(T &res, const T &val) { if (val < res) { res = val; return true; } return false; }
const ll Linf = 0x3f3f3f3f3f3f3f3f;
const int Inf = 0x3f3f3f3f;
const ll Mod = 1e9 + 7;
const ll Mod2 = ll(1e9) + 9;
const int Lim = 1e6 + 5;
const int inv6 = 166666668;
/// ====*====*====*====*====*====*====*====*====*====*====*====*====*====*====*====*====
const int base = 3;
const int N = 1e5 + 5;
const int K = log2(N) + 1;
const int dx[] = {+1, -1, 0, 0};
const int dy[] = {0, 0, +1, -1};
const int block_size = sqrt(2e9) + 2;
int n, k;
int sz[N], f[N];
vector<pii> adj[N];
struct Fenwick {
vector<int> f;
int n = 0;
Fenwick(int n = 0): n(n) { f.assign(n + 1, 0); }
void upd(int u, int x) { for (; u <= n; u += u & -u) f[u] += x; }
int get(int u) { u = min(u, n); int ans = 0; for (; u > 0; u -= u & -u) ans += f[u]; return ans; }
};
int dfs_sz(int u, int p) {
sz[u] = 1;
for (auto &[v, w]: adj[u]) if (v != p && !f[v])
sz[u] += dfs_sz(v, u);
return sz[u];
}
int find_centroid(int u, int p, int n) {
for (auto &[v, w]: adj[u]) if (v != p && !f[v])
if (sz[v] * 2 > n) return find_centroid(v, u, n);
return u;
}
ll ans;
int nsz;
map<int, Fenwick> dp;
int dist[N], high[N], top[N];
vector<int> prior;
void dfs(int u, int p) {
if (p) high[u] = high[p] + 1; else high[u] = 0;
maximize(nsz, high[u]);
if (p) prior.emplace_back(u);
for (auto &[v, w]: adj[u]) if (v != p && !f[v]) {
dist[v] = max(dist[u], w);
if (p == 0) {
top[v] = v;
} else {
top[v] = top[u];
}
dfs(v, u);
}
}
void solve(int u) {
dist[u] = 0;
high[u] = 0;
nsz = 0;
prior.clear();
dfs(u, 0);
stable_sort(all(prior), [&](int x, int y) {
return dist[x] < dist[y];
});
Fenwick sum(nsz);
for (auto &u: prior) {
int w = dist[u];
if (high[u] == 1) {
dp[u] = Fenwick(nsz);
}
int p = top[u];
//cout << u << " " << p << " " << w << " " << high[u] << " ";
if (w - high[u] >= k) {
++ans;
//cout << " + " << 1 << ", ";
} //cout << " + " << sum.get(w - high[u] - k) - dp[p].get(w - high[u] - k) << "\n";
ans += sum.get(w - high[u] - k) - dp[p].get(w - high[u] - k);
sum.upd(high[u], 1);
dp[p].upd(high[u], 1);
}
dp.clear();
}
void build(int u) {
int n = dfs_sz(u, -1);
u = find_centroid(u, -1, n);
solve(u);
f[u] = true;
for (auto &[v, w]: adj[u]) if (!f[v]) build(v);
f[u] = false;
}
void solve() {
cin >> n >> k;
foru(i, 2, n) {
int u, v, w;
cin >> u >> v >> w;
adj[u].emplace_back(v, w);
adj[v].emplace_back(u, w);
}
build(1);
cout << ans * 2;
}
signed main() {
FastIO;
#define task "HOTPOT"
if (fopen(task".inp", "r")) {
freopen(task".inp", "r", stdin);
freopen(task".out", "w", stdout);
}
int ntest = 1;
// cin >> ntest;
while (ntest--) {
//cout << "Case " << q << ": " << "\n";
solve();
cout << "\n";
}
return 0;
}
/** /\_/\
* (= ._.)
* / >TL \>AC
**/
Compilation message
Main.cpp: In function 'int main()':
Main.cpp:155:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
155 | freopen(task".inp", "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:156:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
156 | freopen(task".out", "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
4440 KB |
Output is correct |
2 |
Correct |
1 ms |
4444 KB |
Output is correct |
3 |
Correct |
1 ms |
4444 KB |
Output is correct |
4 |
Correct |
2 ms |
4444 KB |
Output is correct |
5 |
Correct |
2 ms |
4444 KB |
Output is correct |
6 |
Correct |
2 ms |
4536 KB |
Output is correct |
7 |
Correct |
2 ms |
4444 KB |
Output is correct |
8 |
Correct |
2 ms |
4444 KB |
Output is correct |
9 |
Correct |
1 ms |
4444 KB |
Output is correct |
10 |
Correct |
1 ms |
4544 KB |
Output is correct |
11 |
Correct |
1 ms |
4444 KB |
Output is correct |
12 |
Correct |
2 ms |
4444 KB |
Output is correct |
13 |
Correct |
2 ms |
4444 KB |
Output is correct |
14 |
Correct |
2 ms |
4444 KB |
Output is correct |
15 |
Correct |
2 ms |
4444 KB |
Output is correct |
16 |
Correct |
2 ms |
4444 KB |
Output is correct |
17 |
Correct |
2 ms |
4444 KB |
Output is correct |
18 |
Correct |
2 ms |
4444 KB |
Output is correct |
19 |
Correct |
2 ms |
4444 KB |
Output is correct |
20 |
Correct |
1 ms |
4444 KB |
Output is correct |
21 |
Correct |
2 ms |
4444 KB |
Output is correct |
22 |
Correct |
2 ms |
4444 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
4444 KB |
Output is correct |
2 |
Correct |
1 ms |
4444 KB |
Output is correct |
3 |
Correct |
1 ms |
4444 KB |
Output is correct |
4 |
Correct |
2 ms |
4444 KB |
Output is correct |
5 |
Correct |
12 ms |
5652 KB |
Output is correct |
6 |
Correct |
53 ms |
9844 KB |
Output is correct |
7 |
Correct |
96 ms |
15116 KB |
Output is correct |
8 |
Correct |
120 ms |
14968 KB |
Output is correct |
9 |
Correct |
101 ms |
15060 KB |
Output is correct |
10 |
Correct |
126 ms |
15112 KB |
Output is correct |
11 |
Correct |
96 ms |
14944 KB |
Output is correct |
12 |
Correct |
113 ms |
15120 KB |
Output is correct |
13 |
Correct |
102 ms |
15120 KB |
Output is correct |
14 |
Correct |
114 ms |
15108 KB |
Output is correct |
15 |
Correct |
114 ms |
15108 KB |
Output is correct |
16 |
Correct |
115 ms |
15116 KB |
Output is correct |
17 |
Correct |
112 ms |
15112 KB |
Output is correct |
18 |
Correct |
111 ms |
14856 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
4440 KB |
Output is correct |
2 |
Correct |
1 ms |
4444 KB |
Output is correct |
3 |
Correct |
1 ms |
4444 KB |
Output is correct |
4 |
Correct |
2 ms |
4444 KB |
Output is correct |
5 |
Correct |
2 ms |
4444 KB |
Output is correct |
6 |
Correct |
2 ms |
4536 KB |
Output is correct |
7 |
Correct |
2 ms |
4444 KB |
Output is correct |
8 |
Correct |
2 ms |
4444 KB |
Output is correct |
9 |
Correct |
1 ms |
4444 KB |
Output is correct |
10 |
Correct |
1 ms |
4544 KB |
Output is correct |
11 |
Correct |
1 ms |
4444 KB |
Output is correct |
12 |
Correct |
2 ms |
4444 KB |
Output is correct |
13 |
Correct |
2 ms |
4444 KB |
Output is correct |
14 |
Correct |
2 ms |
4444 KB |
Output is correct |
15 |
Correct |
2 ms |
4444 KB |
Output is correct |
16 |
Correct |
2 ms |
4444 KB |
Output is correct |
17 |
Correct |
2 ms |
4444 KB |
Output is correct |
18 |
Correct |
2 ms |
4444 KB |
Output is correct |
19 |
Correct |
2 ms |
4444 KB |
Output is correct |
20 |
Correct |
1 ms |
4444 KB |
Output is correct |
21 |
Correct |
2 ms |
4444 KB |
Output is correct |
22 |
Correct |
2 ms |
4444 KB |
Output is correct |
23 |
Correct |
1 ms |
4444 KB |
Output is correct |
24 |
Correct |
1 ms |
4444 KB |
Output is correct |
25 |
Correct |
1 ms |
4444 KB |
Output is correct |
26 |
Correct |
2 ms |
4444 KB |
Output is correct |
27 |
Correct |
12 ms |
5652 KB |
Output is correct |
28 |
Correct |
53 ms |
9844 KB |
Output is correct |
29 |
Correct |
96 ms |
15116 KB |
Output is correct |
30 |
Correct |
120 ms |
14968 KB |
Output is correct |
31 |
Correct |
101 ms |
15060 KB |
Output is correct |
32 |
Correct |
126 ms |
15112 KB |
Output is correct |
33 |
Correct |
96 ms |
14944 KB |
Output is correct |
34 |
Correct |
113 ms |
15120 KB |
Output is correct |
35 |
Correct |
102 ms |
15120 KB |
Output is correct |
36 |
Correct |
114 ms |
15108 KB |
Output is correct |
37 |
Correct |
114 ms |
15108 KB |
Output is correct |
38 |
Correct |
115 ms |
15116 KB |
Output is correct |
39 |
Correct |
112 ms |
15112 KB |
Output is correct |
40 |
Correct |
111 ms |
14856 KB |
Output is correct |
41 |
Correct |
1 ms |
4444 KB |
Output is correct |
42 |
Correct |
97 ms |
14936 KB |
Output is correct |
43 |
Correct |
112 ms |
15044 KB |
Output is correct |
44 |
Correct |
102 ms |
15108 KB |
Output is correct |
45 |
Correct |
109 ms |
15116 KB |
Output is correct |
46 |
Correct |
97 ms |
15116 KB |
Output is correct |
47 |
Correct |
114 ms |
15108 KB |
Output is correct |
48 |
Correct |
103 ms |
15108 KB |
Output is correct |
49 |
Correct |
122 ms |
14976 KB |
Output is correct |
50 |
Correct |
112 ms |
14912 KB |
Output is correct |
51 |
Correct |
111 ms |
15112 KB |
Output is correct |
52 |
Correct |
73 ms |
9424 KB |
Output is correct |
53 |
Correct |
71 ms |
9432 KB |
Output is correct |
54 |
Correct |
53 ms |
9572 KB |
Output is correct |
55 |
Correct |
77 ms |
9420 KB |
Output is correct |
56 |
Correct |
77 ms |
9424 KB |
Output is correct |
57 |
Correct |
143 ms |
9016 KB |
Output is correct |
58 |
Correct |
118 ms |
9180 KB |
Output is correct |
59 |
Correct |
109 ms |
9172 KB |
Output is correct |
60 |
Correct |
135 ms |
9180 KB |
Output is correct |
61 |
Correct |
145 ms |
9068 KB |
Output is correct |
62 |
Correct |
105 ms |
9160 KB |
Output is correct |
63 |
Correct |
121 ms |
9164 KB |
Output is correct |
64 |
Correct |
133 ms |
9224 KB |
Output is correct |
65 |
Correct |
5 ms |
4696 KB |
Output is correct |
66 |
Correct |
1 ms |
4444 KB |
Output is correct |