#include "race.h"
#include<bits/stdc++.h>
using namespace std;
#define MAX_N 500000
vector < pair < int, int > > adj[200004];
int sz[200004], used[200005] = {0}, d[1000004];
int N, K;
int H[MAX_N][2];
int L[MAX_N];
vector < int > v;
int find_size(int node, int parent) {
sz[node] = 1;
for ( pair <int,int >& A : adj[node]) {
int child = A.first;
if ( used[child] || parent == child) continue;
sz[node] += find_size(child, node);
}
return sz[node];
}
int find_centroid(int node, int parent, int n) {
for ( pair <int, int>& A : adj[node]) {
int child = A.first;
if ( child == parent || used[child] ) continue;
if ( sz[child] * 2 > n) return find_centroid(child, node, n);
}
return node;
}
int ans = -1;
void dfs(int node, int parent, int budjaagaa, int dist, int depth) {
if ( dist > K) return;
if ( budjaagaa) {
if ( d[dist] == -1) d[dist] = depth;
else d[dist] = min(d[dist], depth);
v.push_back(dist);
}
else {
if ( d[K - dist] != -1) {
if ( ans == -1) ans = depth + d[K - dist];
else ans = min(ans, depth + d[K - dist]);
}
}
for ( pair < int, int>&A : adj[node]) {
int child = A.first;
if ( used[child] || child == parent) continue;
dfs(child, node, budjaagaa, dist + A.second, depth + 1);
}
}
int solve(int node) {
int c = find_centroid(node, node, find_size(node, node));
used[c] = 1;
v.clear();
for ( pair <int, int>& A : adj[c]) {
int child = A.first;
if ( used[child]) continue;
dfs(child, c, 0, A.second, 1);
dfs(child, c, 1, A.second, 1);
}
for (int X : v) {
d[X] = -1;
}
for ( pair <int, int>& A : adj[c]) {
int child = A.first;
if ( used[child]) continue;
solve(child);
}
}
int best_path(int N, int K, int H[][2], int L[]){
for (int i = 0; i < (N - 1); i ++) {
adj[H[i][0]].push_back({H[i][1], L[i]});
adj[H[i][1]].push_back({H[i][0], L[i]});
}
for (int i = 0; i <=K; i ++) d[i] = -1;
solve(0);
return ans;
}
void read_input()
{
int i;
cin >> N >> K;
for (i = 0; i < N - 1; i ++) cin >> H[i][0] >> H[i][1] >> L[i];
}
int main()
{
int ans;
read_input();
ans = best_path(N,K,H,L);
cout << ans << endl;
return 0;
}
Compilation message
race.cpp: In function 'int solve(int)':
race.cpp:68:1: warning: no return statement in function returning non-void [-Wreturn-type]
68 | }
| ^
/usr/bin/ld: /tmp/cciDByIT.o: in function `read_input()':
race.cpp:(.text+0x170): multiple definition of `read_input()'; /tmp/ccVK6vFX.o:grader.cpp:(.text+0x0): first defined here
/usr/bin/ld: /tmp/cciDByIT.o: in function `main':
race.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccVK6vFX.o:grader.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status
