# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
946919 | Esgeer | 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;
#include <ext/pb_ds/assoc_container.hpp>
#include <unistd.h>
using namespace __gnu_pbds;
template <class T>
using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#ifndef Local
#pragma GCC optimize("O3,unroll-loops")
#endif
//#define int long long
#define vi vector<int>
#define vvi vector<vi>
//#define pii pair<int, int>
#define vpi vector<pii>
#define vvpi vector<vpi>
#define vb vector<bool>
#define vvb vector<vb>
#define endl '\n'
#define sp << " " <<
#define F(i, s, n) for(int i = s; i < n; i++)
#define pb push_back
#define fi first
#define se second
#include "race.h"
ll inf = 1e18;
int32_t l[200005];
int32_t h[200005][2];
typedef long long ll;
typedef pair<ll, ll> pii;
#define pb push_back
#define f first
#define s second
const int maxn = 2e5 + 1;
vector<pii> adj[maxn];
map<ll, ll> info[maxn];
ll dist[maxn], sum[maxn]; // define these relative to root
int N, K;
ll ret;
void precomp(int u, int p, ll c, int h) {
info[u][c] = h;
sum[u] = c;
dist[u] = h;
for (auto n : adj[u]) {
if (p == n.f) { continue; }
precomp(n.f, u, c + n.s, h + 1);
}
}
void small_to_large_merge(int u, int p) {
ll target = K + 2 * sum[u];
for (auto n : adj[u]) {
if (n.f == p) { continue; }
small_to_large_merge(n.f, u);
if (info[n.f].size() > info[u].size()) { swap(info[n.f], info[u]); }
for (auto i : info[n.f]) {
if (info[u].find(target - i.f) != info[u].end()) {
ret = min(ret, info[u][target - i.f] + i.s - 2 * dist[u]);
}
}
for (auto i : info[n.f]) {
if (info[u].find(i.f) == info[u].end()) {
info[u].insert(i);
} else {
info[u][i.f] = min(info[u][i.f], i.s);
}
}
}
}
int best_path(int n, int k, int edges[][2], int weights[]) {
if (k == 1) { return 0; }
N = n;
K = k;
ret = INT_MAX;
for (int i = 0; i < n - 1; i++) {
int u = edges[i][0];
int v = edges[i][1];
adj[u].pb(pii(v, weights[i]));
adj[v].pb(pii(u, weights[i]));
}
precomp(0, -1, 0, 0);
small_to_large_merge(0, -1);
return ret == INT_MAX ? -1 : ret;
}
/*void solve() {
int32_t n, k;
cin >> n >> k;
F(i, 0, n-1) cin >> h[i][0] >> h[i][1];
F(i, 0, n-1) cin >> l[i];
cout << best_path(n, k, h, l) << endl;
}
void setIO() {
ios_base::sync_with_stdio(0); cin.tie(0);
#ifdef Local
freopen("local.in", "r", stdin);
freopen("local.out", "w", stdout);
#else
// freopen("disrupt.in","r",stdin);
// freopen("disrupt.out","w",stdout);
#endif
}
signed main() {
setIO();
int t = 1;
//cin >> t;
while(t--) solve();
}*/