| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 851364 | mat_jur | 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;
#ifdef DEBUG
auto&operator<<(auto &o, pair<auto, auto> p) {o << "(" << p.first << ", " << p.second << ")"; return o;}
auto operator<<(auto &o, auto x)->decltype(x.end(), o) {o<<"{"; for(auto e : x) o<<e<<", "; return o<<"}";}
#define debug(X) cerr << "["#X"]: " << X << '\n';
#else
#define debug(X) ;
#endif
#define ll long long
#define all(v) (v).begin(), (v).end()
#define FOR(i,l,r) for(int i=(l);i<=(r);++i)
#define ROF(i,r,l) for(int i=(r);i>=(l);--i)
#define REP(i,n) FOR(i,0,(n)-1)
#define ssize(x) int(x.size())
#define fi first
#define se second
#define mp make_pair
#define eb emplace_back
int best_path(int n, int k, int h[][2], int l[]) { vector<vector<pair<int, int>>> G(n); REP(i, n-1) { G[h[i][0]].eb(mp(h[i][1], l[i])); G[h[i][1]].eb(mp(h[i][0], l[i])); } const int inf = 1e9; int res = inf; auto merge = [&](pair<pair<int, int>, map<int, int>> &a, pair<pair<int, int>, map<int, int>> &b) { if (ssize(a.se) < ssize(b.se)) swap(a, b); for (auto x : b.se) { int key = x.fi+b.fi.fi; if(a.se.find((k-key)-a.fi.fi) != a.se.end()) res = min(res, a.se[(k-key)-a.fi.fi]+a.fi.se+x.se+b.fi.se); } for (auto x : b.se) { int key = x.fi+b.fi.fi; if (a.se.find(key-a.fi.fi) == a.se.end()) a.se[key-a.fi.fi] = inf; a.se[key-a.fi.fi] = min(a.se[key-a.fi.fi], x.se+b.fi.se-a.fi.se); } return a; }; function<pair<pair<int, int>, map<int, int>>(int, int)> dfs = [&](int v, int p) { pair<pair<int, int>, map<int, int>> A; A.fi.fi = A.fi.se = 0; A.se[0] = 0; for (auto e : G[v]) { int u = e.fi, w = e.se; if (u == p) continue; pair<pair<int, int>, map<int, int>> B = dfs(u, v); B.fi.fi += w; B.fi.se++; merge(A, B); } return A; }; dfs(0, -1); if (res == inf) return -1; return res;} #ifdef LOCALint main () { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); int n, k; cin >> n >> k; int h[n-1][2]; int l[n-1]; REP(i, n-1) { cin >> h[i][0] >> h[i][1]; } REP(i, n-1) { cin >> l[i]; } cout << best_path(n, k, h, l) << '\n'; return 0;}
#endif