| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 923856 | Whisper | 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 "race.h"
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using T = tuple<ll, ll, ll>;
#define int long long
#define Base 41
#define sz(a) (int)a.size()
#define FOR(i, a, b) for ( int i = a ; i <= b ; i++ )
#define FORD(i, a, b) for (int i = b; i >= a; i --)
#define REP(i, n) for (int i = 0; i < n; ++i)
#define REPD(i, n) for (int i = n - 1; i >= 0; --i)
#define all(x) x.begin() , x.end()
#define pii pair<int , int>
#define fi first
#define se second
#define Lg(x) 31 - __builtin_clz(x)
#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)
constexpr ll LINF = (1ll << 60);
constexpr int INF = (1ll << 30);
constexpr int MAX = 2e5 + 5;
constexpr int Mod = 1e9 + 7;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
template <class X, class Y>
bool minimize(X &x, const Y &y){
X eps = 1e-9;
if (x > y + eps) {x = y; return 1;}
return 0;
}
template <class X, class Y>
bool maximize(X &x, const Y &y){
X eps = 1e-9;
if (x + eps < y) {x = y; return 1;}
return 0;
}
int numNode, k;
vector<pii> adj[MAX];
int sz[MAX], del[MAX];
void reSubsize(int u, int p){
sz[u] = 1;
for (auto&[v, w] : adj[u]) if(v ^ p){
if (del[v]) continue;
reSubsize(v, u);
sz[u] += sz[v];
}
}
int getCentroid(int u, int p, int siz){
for (auto&[v, w] : adj[u]) if(v ^ p){
if (!del[v] && sz[v] * 2 > siz) return getCentroid(v, u, siz);
}
return u;
}
int f[5 * MAX];
int ans = LINF;
vector<int> save;
void dfs(int u, int p, int l, int dep, bool ok){
if (l > k) return;
if (ok) minimize(ans, f[k - l] + dep);
else{
minimize(f[l], dep);
save.push_back(l);
}
for (auto&[v, w] : adj[u]) if(v ^ p){
if (!del[v]) dfs(v, u, l + w, dep + 1, ok);
}
}
void decompose(int root){
reSubsize(root, -1);
int siz = sz[root];
root = getCentroid(root, -1, siz);
del[root] = 1;
for (auto&[v, w] : adj[root]){
if (del[v]) continue;
dfs(v, root, w, 1, 1);
dfs(v, root, w, 1, 0);
}
for (auto&v : save) f[v] = 1e18;
save.clear();
for (auto&[v, w] : adj[root]) if (!del[v]){
decompose(v);
}
}
int best_path(int n, int k, int h[][2], int l[]) {
numNode = N, k = K;
for (int i = 1; i < numNode; ++i){
int u = H[i][0], v = H[i][1], w = L[i];
++u, ++v;
adj[u].push_back({v, w});
adj[v].push_back({u, w});
}
memset(f, 0x3f, sizeof f);
decompose(1);
return (ans > 1e15 ? -1 : ans);
}