#include <bits/stdc++.h>
#define FIO ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define ll long long
#define pb push_back
#define mp make_pair
#define F first
#define S second
#define pll pair < ll, ll >
using namespace std;
const int N = 1e5+10;
int n, k;
vector < pll > edges[N];
ll maxmass[N];
ll siz[N];
ll dep[N];
bool rip[N];
ll fenwick[N];
vector < pll > querries;
void add( int x, ll v ) {
for(x; x < N; x += x & -x) fenwick[x] += v;
return;
}
ll sum( int x ) {
ll out = 0;
for(x; x > 0; x -= x & -x) out += fenwick[x];
return out;
}
void dfs( int x, int par ) {
if(par!=-1) dep[x] = dep[par] + 1;
else dep[x] = 0;
if(par==-1) maxmass[x] = 0;
siz[x] = 1;
for(int i = 0; i < (int) edges[x].size(); i++) {
if(edges[x][i].F != par && !rip[edges[x][i].F]) {
maxmass[edges[x][i].F] = max(maxmass[x], edges[x][i].S);
dfs(edges[x][i].F, x);
siz[x] += siz[edges[x][i].F];
}
}
return;
}
int find_centroid( int x, int par, int treesiz ) {
for(int i = 0; i < (int) edges[x].size(); i++) if(!rip[edges[x][i].F] && siz[edges[x][i].F] > treesiz/2 && edges[x][i].F != par) return find_centroid(edges[x][i].F, x, treesiz);
return x;
}
void add_to_q( int x, int par ) {
if(dep[x]!=0) querries.pb(mp(maxmass[x], dep[x]));
for(int i = 0; i < (int) edges[x].size(); i++) {
if(edges[x][i].F != par && (!rip[edges[x][i].F])) add_to_q(edges[x][i].F, x);
}
return;
}
ll dac( int x ) {
ll sol = 0;
dfs(x, -1);
if(siz[x] == 1) return 0;
x = find_centroid(x, -1, siz[x]);
dfs(x, -1);
add_to_q(x, -1);
sort(querries.begin(), querries.end());
for(int i = 0; i < (int) querries.size(); i++) {
sol += sum(querries[i].F - querries[i].S - k) + (int) (querries[i].F - querries[i].S >= k);
add(querries[i].S, 1);
}
for(int i = 0; i < (int) querries.size(); i++) add(querries[i].S, -1);
querries.clear();
rip[x] = 1;
for(int i = 0; i < (int) edges[x].size(); i++) {
if(!rip[edges[x][i].F]) {
add_to_q(edges[x][i].F, -1);
for(int j = 0; j < querries.size(); j++) {
sol -= sum(querries[j].F - querries[j].S - k);
add(querries[j].S, 1);
}
for(int j = 0; j < querries.size(); j++) {
add(querries[j].S, -1);
}
querries.clear();
sol += dac(edges[x][i].F)*2;
}
}
return sol;
}
int main( void ) {
FIO
cin >> n >> k;
int tempa, tempb, tempc;
for(int i = 0; i < n - 1; i++) {
cin >> tempa >> tempb >> tempc;
edges[--tempa].pb(mp(--tempb, tempc));
edges[tempb].pb(mp(tempa, tempc));
}
cout << dac(0) * 2;
return 0;
}
Compilation message
Main.cpp: In function 'void add(int, long long int)':
Main.cpp:23:6: warning: statement has no effect [-Wunused-value]
23 | for(x; x < N; x += x & -x) fenwick[x] += v;
| ^
Main.cpp: In function 'long long int sum(int)':
Main.cpp:29:6: warning: statement has no effect [-Wunused-value]
29 | for(x; x > 0; x -= x & -x) out += fenwick[x];
| ^
Main.cpp: In function 'long long int dac(int)':
Main.cpp:81:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
81 | for(int j = 0; j < querries.size(); j++) {
| ~~^~~~~~~~~~~~~~~~~
Main.cpp:85:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
85 | for(int j = 0; j < querries.size(); j++) {
| ~~^~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
5720 KB |
Output is correct |
| 2 |
Correct |
2 ms |
5724 KB |
Output is correct |
| 3 |
Incorrect |
2 ms |
5724 KB |
Output isn't correct |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
5724 KB |
Output is correct |
| 2 |
Correct |
2 ms |
5724 KB |
Output is correct |
| 3 |
Incorrect |
2 ms |
5724 KB |
Output isn't correct |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
5720 KB |
Output is correct |
| 2 |
Correct |
2 ms |
5724 KB |
Output is correct |
| 3 |
Incorrect |
2 ms |
5724 KB |
Output isn't correct |
| 4 |
Halted |
0 ms |
0 KB |
- |
