#include<bits/stdc++.h>
using namespace std;
#define FOR(i, a, b) for(int i = (a), _b = (b); i <= _b; ++i)
#define FORD(i, b, a) for(int i = (b), _a = (a); i >= _a; --i)
#define REP(i, a, b) for(int i = (a), _b = (b); i < _b; ++i)
#define REPD(i, b, a) for(int i = (b), _a = (a); i > _a; --i)
#define MASK(i) (1LL << (i))
#define BIT(mask, i) (((mask) >> (i)) & 1)
#define __builtin_popcount __builtin_popcountll
#define all(val) val.begin(), val.end()
#define ll long long
#define ull unsigned long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define sz(v) (int)v.size()
#define fi first
#define se second
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll Rand(ll l, ll r) {return l + rng() % (r - l + 1);}
template<class X, class Y>
bool minimize(X &x, const Y &y) {
if (x > y) {
x = y;
return true;
} else return false;
}
template<class X, class Y>
bool maximize(X &x, const Y &y) {
if (x < y) {
x = y;
return true;
} else return false;
}
template<class T>
T Abs(const T &x) {
return (x < 0 ? -x : x);
}
const int mod = 1e9 + 7;
const int N = 1e5 + 5;
int bit[N];
void update(int i, int val) {
for(; i < N; i += i & -i) bit[i] += val;
}
int get(int i) {
int res(0);
for(; i; i -= i & -i) res += bit[i];
return res;
}
int n, k;
int sz[N], cnt[N];
bool del[N];
vector<pii> g[N], res;
ll ans;
int dfs_size(int u, int p = 0) {
sz[u] = 1;
for(auto [v, w] : g[u]) if(v != p && !del[v]) sz[u] += dfs_size(v, u);
return sz[u];
}
int find_centroid(int u, int p, int num) {
for(auto [v, w] : g[u]) if(v != p && !del[v] && sz[v] > num / 2)
return find_centroid(v, u, num);
return u;
}
void dfs(int u, int p, int dep, int val) {
res.emplace_back(val, dep);
for(auto [v, w] : g[u]) if(v != p && !del[v])
dfs(v, u, dep + 1, max(val, w));
}
ll compute(vector<pii> &res) {
sort(all(res));
ll ans(0);
for(auto [w, len] : res) {
if(w >= len) ans += get(w - len);
update(k + len, 1);
}
for(auto [w, len] : res) {
update(k + len, -1);
}
return ans;
}
void decomposition(int u) {
u = find_centroid(u, 0, dfs_size(u));
del[u] = 1;
res.clear();
dfs(u, 0, 0, 0);
ans += compute(res);
for(auto [v, w] : g[u]) if(!del[v]) {
res.clear();
dfs(v, u, 1, w);
ans -= compute(res);
}
for(auto [v, w] : g[u]) if(!del[v])
decomposition(v);
}
void process() {
cin >> n >> k;
REP(i, 1, n) {
int u, v, w; cin >> u >> v >> w;
g[u].emplace_back(v, w);
g[v].emplace_back(u, w);
}
decomposition(1);
cout << ans * 2 << '\n';
}
signed main() {
if(fopen("COCI21_janjetina.inp","r")) {
freopen("COCI21_janjetina.inp","r",stdin);
freopen("COCI21_janjetina.out","w",stdout);
}
ios::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
// clock_t start = clock();
int ntests = 1;
// cin >> ntests;
while(ntests--) process();
// cerr << "Time elapsed: " << clock() - start << " ms!\n";
return 0;
}
// https://oj.uz/problem/view/COCI21_janjetina
Compilation message
Main.cpp: In function 'int dfs_size(int, int)':
Main.cpp:64:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
64 | for(auto [v, w] : g[u]) if(v != p && !del[v]) sz[u] += dfs_size(v, u);
| ^
Main.cpp: In function 'int find_centroid(int, int, int)':
Main.cpp:69:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
69 | for(auto [v, w] : g[u]) if(v != p && !del[v] && sz[v] > num / 2)
| ^
Main.cpp: In function 'void dfs(int, int, int, int)':
Main.cpp:76:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
76 | for(auto [v, w] : g[u]) if(v != p && !del[v])
| ^
Main.cpp: In function 'long long int compute(std::vector<std::pair<int, int> >&)':
Main.cpp:83:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
83 | for(auto [w, len] : res) {
| ^
Main.cpp:87:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
87 | for(auto [w, len] : res) {
| ^
Main.cpp: In function 'void decomposition(int)':
Main.cpp:99:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
99 | for(auto [v, w] : g[u]) if(!del[v]) {
| ^
Main.cpp:104:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
104 | for(auto [v, w] : g[u]) if(!del[v])
| ^
Main.cpp: In function 'int main()':
Main.cpp:121:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
121 | freopen("COCI21_janjetina.inp","r",stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:122:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
122 | freopen("COCI21_janjetina.out","w",stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
2652 KB |
Output is correct |
2 |
Correct |
1 ms |
2652 KB |
Output is correct |
3 |
Correct |
1 ms |
2652 KB |
Output is correct |
4 |
Correct |
2 ms |
2840 KB |
Output is correct |
5 |
Correct |
2 ms |
2908 KB |
Output is correct |
6 |
Correct |
2 ms |
2908 KB |
Output is correct |
7 |
Correct |
2 ms |
2908 KB |
Output is correct |
8 |
Correct |
2 ms |
2908 KB |
Output is correct |
9 |
Correct |
1 ms |
2908 KB |
Output is correct |
10 |
Correct |
1 ms |
2908 KB |
Output is correct |
11 |
Correct |
1 ms |
2908 KB |
Output is correct |
12 |
Correct |
2 ms |
2908 KB |
Output is correct |
13 |
Correct |
2 ms |
2908 KB |
Output is correct |
14 |
Correct |
1 ms |
2908 KB |
Output is correct |
15 |
Correct |
2 ms |
2908 KB |
Output is correct |
16 |
Correct |
2 ms |
2908 KB |
Output is correct |
17 |
Correct |
2 ms |
2908 KB |
Output is correct |
18 |
Correct |
2 ms |
2908 KB |
Output is correct |
19 |
Correct |
1 ms |
2908 KB |
Output is correct |
20 |
Correct |
1 ms |
2908 KB |
Output is correct |
21 |
Correct |
2 ms |
2908 KB |
Output is correct |
22 |
Correct |
2 ms |
2908 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
2652 KB |
Output is correct |
2 |
Correct |
1 ms |
2652 KB |
Output is correct |
3 |
Correct |
0 ms |
2652 KB |
Output is correct |
4 |
Correct |
2 ms |
2908 KB |
Output is correct |
5 |
Correct |
14 ms |
4188 KB |
Output is correct |
6 |
Correct |
98 ms |
9200 KB |
Output is correct |
7 |
Correct |
113 ms |
15072 KB |
Output is correct |
8 |
Correct |
231 ms |
15816 KB |
Output is correct |
9 |
Correct |
130 ms |
15052 KB |
Output is correct |
10 |
Correct |
241 ms |
15484 KB |
Output is correct |
11 |
Correct |
156 ms |
15060 KB |
Output is correct |
12 |
Correct |
172 ms |
15580 KB |
Output is correct |
13 |
Correct |
176 ms |
15164 KB |
Output is correct |
14 |
Correct |
205 ms |
15504 KB |
Output is correct |
15 |
Correct |
244 ms |
15308 KB |
Output is correct |
16 |
Correct |
200 ms |
15464 KB |
Output is correct |
17 |
Correct |
185 ms |
15308 KB |
Output is correct |
18 |
Correct |
184 ms |
15420 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
2652 KB |
Output is correct |
2 |
Correct |
1 ms |
2652 KB |
Output is correct |
3 |
Correct |
1 ms |
2652 KB |
Output is correct |
4 |
Correct |
2 ms |
2840 KB |
Output is correct |
5 |
Correct |
2 ms |
2908 KB |
Output is correct |
6 |
Correct |
2 ms |
2908 KB |
Output is correct |
7 |
Correct |
2 ms |
2908 KB |
Output is correct |
8 |
Correct |
2 ms |
2908 KB |
Output is correct |
9 |
Correct |
1 ms |
2908 KB |
Output is correct |
10 |
Correct |
1 ms |
2908 KB |
Output is correct |
11 |
Correct |
1 ms |
2908 KB |
Output is correct |
12 |
Correct |
2 ms |
2908 KB |
Output is correct |
13 |
Correct |
2 ms |
2908 KB |
Output is correct |
14 |
Correct |
1 ms |
2908 KB |
Output is correct |
15 |
Correct |
2 ms |
2908 KB |
Output is correct |
16 |
Correct |
2 ms |
2908 KB |
Output is correct |
17 |
Correct |
2 ms |
2908 KB |
Output is correct |
18 |
Correct |
2 ms |
2908 KB |
Output is correct |
19 |
Correct |
1 ms |
2908 KB |
Output is correct |
20 |
Correct |
1 ms |
2908 KB |
Output is correct |
21 |
Correct |
2 ms |
2908 KB |
Output is correct |
22 |
Correct |
2 ms |
2908 KB |
Output is correct |
23 |
Correct |
1 ms |
2652 KB |
Output is correct |
24 |
Correct |
1 ms |
2652 KB |
Output is correct |
25 |
Correct |
0 ms |
2652 KB |
Output is correct |
26 |
Correct |
2 ms |
2908 KB |
Output is correct |
27 |
Correct |
14 ms |
4188 KB |
Output is correct |
28 |
Correct |
98 ms |
9200 KB |
Output is correct |
29 |
Correct |
113 ms |
15072 KB |
Output is correct |
30 |
Correct |
231 ms |
15816 KB |
Output is correct |
31 |
Correct |
130 ms |
15052 KB |
Output is correct |
32 |
Correct |
241 ms |
15484 KB |
Output is correct |
33 |
Correct |
156 ms |
15060 KB |
Output is correct |
34 |
Correct |
172 ms |
15580 KB |
Output is correct |
35 |
Correct |
176 ms |
15164 KB |
Output is correct |
36 |
Correct |
205 ms |
15504 KB |
Output is correct |
37 |
Correct |
244 ms |
15308 KB |
Output is correct |
38 |
Correct |
200 ms |
15464 KB |
Output is correct |
39 |
Correct |
185 ms |
15308 KB |
Output is correct |
40 |
Correct |
184 ms |
15420 KB |
Output is correct |
41 |
Correct |
1 ms |
2652 KB |
Output is correct |
42 |
Correct |
157 ms |
14872 KB |
Output is correct |
43 |
Correct |
225 ms |
15536 KB |
Output is correct |
44 |
Correct |
125 ms |
15052 KB |
Output is correct |
45 |
Correct |
221 ms |
15308 KB |
Output is correct |
46 |
Correct |
149 ms |
15060 KB |
Output is correct |
47 |
Correct |
189 ms |
15524 KB |
Output is correct |
48 |
Correct |
199 ms |
15052 KB |
Output is correct |
49 |
Correct |
248 ms |
15312 KB |
Output is correct |
50 |
Correct |
205 ms |
15356 KB |
Output is correct |
51 |
Correct |
179 ms |
15476 KB |
Output is correct |
52 |
Correct |
80 ms |
9676 KB |
Output is correct |
53 |
Correct |
68 ms |
10188 KB |
Output is correct |
54 |
Correct |
57 ms |
9740 KB |
Output is correct |
55 |
Correct |
71 ms |
10196 KB |
Output is correct |
56 |
Correct |
91 ms |
10184 KB |
Output is correct |
57 |
Correct |
173 ms |
9436 KB |
Output is correct |
58 |
Correct |
166 ms |
9692 KB |
Output is correct |
59 |
Correct |
162 ms |
9744 KB |
Output is correct |
60 |
Correct |
185 ms |
9748 KB |
Output is correct |
61 |
Correct |
170 ms |
9692 KB |
Output is correct |
62 |
Correct |
121 ms |
9428 KB |
Output is correct |
63 |
Correct |
156 ms |
9800 KB |
Output is correct |
64 |
Correct |
168 ms |
9924 KB |
Output is correct |
65 |
Correct |
6 ms |
3164 KB |
Output is correct |
66 |
Correct |
1 ms |
2652 KB |
Output is correct |