#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 5;
int n, k, a, b, w, treesz[N];
bool isblocked[N];
struct Edge{
int b, w;
};
vector<Edge> tree[N];
struct Item{
int w, d;
bool operator < (const Item &sc) const{
if(w == sc.w) return d < sc.d;
else return w < sc.w;
}
};
struct Fenwick{
int tree[N];
stack<pair<int, int>> hist;
int getsum(int r){
int sum = 0;
for(int i = r; i > 0; i -= i & -i) sum += tree[i];
return sum;
}
int query(int l, int r){
if(l > r) return 0;
return getsum(r) - getsum(l - 1);
}
void update(int pos, int val, bool addhist = true){
if(addhist) hist.push({pos, val});
for(int i = pos; i < N; i += i & -i) tree[i] += val;
}
void clear(){
while(!hist.empty()){
update(hist.top().first, -hist.top().second, false);
hist.pop();
}
}
};
Fenwick fw;
int calcsz(int v, int p){
treesz[v] = 1;
for(auto e : tree[v]){
if(e.b != p && !isblocked[e.b]) treesz[v] += calcsz(e.b, v);
}
return treesz[v];
}
int findcent(int v, int p, int sz){
for(auto e : tree[v]){
if(e.b != p && !isblocked[e.b] && treesz[e.b] >= sz / 2){
return findcent(e.b, v, sz);
}
}
return v;
}
void dfs(int v, int p, int d, int w, vector<Item> &vec){
vec.push_back({w, d});
for(auto e : tree[v]){
if(e.b != p && !isblocked[e.b]){
dfs(e.b, v, d + 1, max(w, e.w), vec);
}
}
}
long long centdecomp(int v){
int sz = calcsz(v, 0);
int cent = findcent(v, 0, sz);
long long ans = 0;
vector<Item> total, cur;
for(auto e : tree[cent]){
if(!isblocked[e.b]){
cur.clear();
dfs(e.b, cent, 1, e.w, cur);
sort(cur.begin(), cur.end());
for(auto itm : cur){
if(itm.w - itm.d >= k) ans += 1;
ans -= fw.query(0, itm.w - itm.d - k);
fw.update(itm.d, 1);
total.push_back(itm);
}
fw.clear();
}
}
sort(total.begin(), total.end());
for(auto itm : total){
ans += fw.query(0, itm.w - itm.d - k);
fw.update(itm.d, 1);
}
fw.clear();
isblocked[cent] = true;
for(auto e : tree[cent]){
if(!isblocked[e.b]){
ans += centdecomp(e.b);
}
}
return ans;
}
int main(){
ios_base::sync_with_stdio(false);cin.tie(NULL);
cin >> n >> k;
for(int i = 1; i <= n - 1; i++){
cin >> a >> b >> w;
tree[a].push_back({b, w});
tree[b].push_back({a, w});
}
cout << centdecomp(1) * 2;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
2644 KB |
Output is correct |
2 |
Correct |
2 ms |
2644 KB |
Output is correct |
3 |
Correct |
2 ms |
2644 KB |
Output is correct |
4 |
Correct |
4 ms |
2772 KB |
Output is correct |
5 |
Correct |
4 ms |
2772 KB |
Output is correct |
6 |
Correct |
4 ms |
2772 KB |
Output is correct |
7 |
Correct |
4 ms |
2812 KB |
Output is correct |
8 |
Correct |
5 ms |
2772 KB |
Output is correct |
9 |
Correct |
3 ms |
2692 KB |
Output is correct |
10 |
Correct |
3 ms |
2772 KB |
Output is correct |
11 |
Correct |
3 ms |
2732 KB |
Output is correct |
12 |
Correct |
3 ms |
2772 KB |
Output is correct |
13 |
Correct |
3 ms |
2772 KB |
Output is correct |
14 |
Correct |
4 ms |
2772 KB |
Output is correct |
15 |
Correct |
3 ms |
2772 KB |
Output is correct |
16 |
Correct |
3 ms |
2772 KB |
Output is correct |
17 |
Correct |
3 ms |
2684 KB |
Output is correct |
18 |
Correct |
3 ms |
2772 KB |
Output is correct |
19 |
Correct |
4 ms |
2720 KB |
Output is correct |
20 |
Correct |
4 ms |
2772 KB |
Output is correct |
21 |
Correct |
3 ms |
2772 KB |
Output is correct |
22 |
Correct |
3 ms |
2772 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
2644 KB |
Output is correct |
2 |
Correct |
2 ms |
2644 KB |
Output is correct |
3 |
Correct |
2 ms |
2644 KB |
Output is correct |
4 |
Correct |
4 ms |
2772 KB |
Output is correct |
5 |
Correct |
27 ms |
4172 KB |
Output is correct |
6 |
Correct |
162 ms |
9884 KB |
Output is correct |
7 |
Correct |
300 ms |
16808 KB |
Output is correct |
8 |
Correct |
373 ms |
17460 KB |
Output is correct |
9 |
Correct |
336 ms |
16984 KB |
Output is correct |
10 |
Correct |
377 ms |
17340 KB |
Output is correct |
11 |
Correct |
330 ms |
16828 KB |
Output is correct |
12 |
Correct |
356 ms |
17532 KB |
Output is correct |
13 |
Correct |
360 ms |
16960 KB |
Output is correct |
14 |
Correct |
357 ms |
17312 KB |
Output is correct |
15 |
Correct |
404 ms |
17280 KB |
Output is correct |
16 |
Correct |
359 ms |
17256 KB |
Output is correct |
17 |
Correct |
366 ms |
17200 KB |
Output is correct |
18 |
Correct |
341 ms |
17244 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
2644 KB |
Output is correct |
2 |
Correct |
2 ms |
2644 KB |
Output is correct |
3 |
Correct |
2 ms |
2644 KB |
Output is correct |
4 |
Correct |
4 ms |
2772 KB |
Output is correct |
5 |
Correct |
4 ms |
2772 KB |
Output is correct |
6 |
Correct |
4 ms |
2772 KB |
Output is correct |
7 |
Correct |
4 ms |
2812 KB |
Output is correct |
8 |
Correct |
5 ms |
2772 KB |
Output is correct |
9 |
Correct |
3 ms |
2692 KB |
Output is correct |
10 |
Correct |
3 ms |
2772 KB |
Output is correct |
11 |
Correct |
3 ms |
2732 KB |
Output is correct |
12 |
Correct |
3 ms |
2772 KB |
Output is correct |
13 |
Correct |
3 ms |
2772 KB |
Output is correct |
14 |
Correct |
4 ms |
2772 KB |
Output is correct |
15 |
Correct |
3 ms |
2772 KB |
Output is correct |
16 |
Correct |
3 ms |
2772 KB |
Output is correct |
17 |
Correct |
3 ms |
2684 KB |
Output is correct |
18 |
Correct |
3 ms |
2772 KB |
Output is correct |
19 |
Correct |
4 ms |
2720 KB |
Output is correct |
20 |
Correct |
4 ms |
2772 KB |
Output is correct |
21 |
Correct |
3 ms |
2772 KB |
Output is correct |
22 |
Correct |
3 ms |
2772 KB |
Output is correct |
23 |
Correct |
2 ms |
2644 KB |
Output is correct |
24 |
Correct |
2 ms |
2644 KB |
Output is correct |
25 |
Correct |
2 ms |
2644 KB |
Output is correct |
26 |
Correct |
4 ms |
2772 KB |
Output is correct |
27 |
Correct |
27 ms |
4172 KB |
Output is correct |
28 |
Correct |
162 ms |
9884 KB |
Output is correct |
29 |
Correct |
300 ms |
16808 KB |
Output is correct |
30 |
Correct |
373 ms |
17460 KB |
Output is correct |
31 |
Correct |
336 ms |
16984 KB |
Output is correct |
32 |
Correct |
377 ms |
17340 KB |
Output is correct |
33 |
Correct |
330 ms |
16828 KB |
Output is correct |
34 |
Correct |
356 ms |
17532 KB |
Output is correct |
35 |
Correct |
360 ms |
16960 KB |
Output is correct |
36 |
Correct |
357 ms |
17312 KB |
Output is correct |
37 |
Correct |
404 ms |
17280 KB |
Output is correct |
38 |
Correct |
359 ms |
17256 KB |
Output is correct |
39 |
Correct |
366 ms |
17200 KB |
Output is correct |
40 |
Correct |
341 ms |
17244 KB |
Output is correct |
41 |
Correct |
2 ms |
2644 KB |
Output is correct |
42 |
Correct |
318 ms |
16928 KB |
Output is correct |
43 |
Correct |
350 ms |
17500 KB |
Output is correct |
44 |
Correct |
346 ms |
16980 KB |
Output is correct |
45 |
Correct |
361 ms |
17280 KB |
Output is correct |
46 |
Correct |
359 ms |
17084 KB |
Output is correct |
47 |
Correct |
353 ms |
17512 KB |
Output is correct |
48 |
Correct |
347 ms |
16960 KB |
Output is correct |
49 |
Correct |
352 ms |
17256 KB |
Output is correct |
50 |
Correct |
388 ms |
17268 KB |
Output is correct |
51 |
Correct |
354 ms |
17260 KB |
Output is correct |
52 |
Correct |
146 ms |
10444 KB |
Output is correct |
53 |
Correct |
144 ms |
10708 KB |
Output is correct |
54 |
Correct |
99 ms |
10212 KB |
Output is correct |
55 |
Correct |
123 ms |
10724 KB |
Output is correct |
56 |
Correct |
138 ms |
10744 KB |
Output is correct |
57 |
Correct |
304 ms |
11128 KB |
Output is correct |
58 |
Correct |
275 ms |
11200 KB |
Output is correct |
59 |
Correct |
313 ms |
11624 KB |
Output is correct |
60 |
Correct |
288 ms |
11252 KB |
Output is correct |
61 |
Correct |
300 ms |
11600 KB |
Output is correct |
62 |
Correct |
268 ms |
10828 KB |
Output is correct |
63 |
Correct |
267 ms |
11072 KB |
Output is correct |
64 |
Correct |
337 ms |
11224 KB |
Output is correct |
65 |
Correct |
12 ms |
3056 KB |
Output is correct |
66 |
Correct |
2 ms |
2644 KB |
Output is correct |