# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
636540 | gun_gan | Race (IOI11_race) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
int best_path(int n, int k, int h[][2], int l[]) {
vector<pair<int,int>> g[n];
vector<int> deg(n);
for(int i = 0; i < n - 1; i++) {
g[h[i][0]].push_back({h[i][1], l[i]});
g[h[i][1]].push_back({h[i][0], l[i]});
deg[h[i][0]]++;
deg[h[i][1]]++;
}
queue<pair<int,int>> q;
vector<vector<int>> dist(n + 1, vector<int>(k + 1, -1)), par(n + 1, vector<int>(k + 1, -1));
for(int i = 0; i < n; i++) {
q.push({i, 0});
dist[i][0] = 0;
par[i][0] = i;
}
while(!q.empty()) {
auto [v, w] = q.front(); q.pop();
// cout << v << " " << w << '\n';
for(auto [u, c] : g[v]) {
if(w + c <= k && dist[u][w + c] == -1 && u != par[v][w]) {
dist[u][w + c] = dist[v][w] + 1;
par[u][w + c] = v;
q.push({u, w + c});
}
}
}
int ret = 1e9;
for(int i = 0; i < n; i++) {
// cout << dist[i][k] << '\n';
if(dist[i][k] != -1) ret = min(ret, dist[i][k]);
}
return (ret == 1e9 ? -1 : ret);
}
int main() {
int n, k;
cin >> n >> k;
int h[n][2], l[n];
for(int i = 0; i < n - 1; i++) {
cin >> h[i][0] >> h[i][1];
}
for(int i = 0; i < n - 1; i++) {
cin >> l[i];
}
cout << best_path(n, k, h, l) << '\n';
}