Submission #1082295

#	Time	Username	Problem	Language	Result	Execution time	Memory
1082295		thieunguyenhuy	Race (IOI11_race)	C++17	0 / 100	2 ms	12636 KiB

race

#ifndef hwe
    #include "race.h"
#endif

#include <bits/stdc++.h>
using namespace std;

#define popcount(n) (__builtin_popcountll((n)))
#define clz(n) (__builtin_clzll((n)))
#define ctz(n) (__builtin_ctzll((n)))
#define lg(n) (63 - __builtin_clzll((n)))
#define BIT(n, i) (((n) >> (i)) & 1ll)
#define MASK(i) (1ll << (i))
#define FLIP(n, i) ((n) ^ (1ll << (i)))
#define ON(n, i) ((n) | MASK(i))
#define OFF(n, i) ((n) & ~MASK(i))

#define Int __int128
#define fi first
#define se second

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<long long, long long> pll;
typedef pair<long long, int> pli;
typedef pair<int, long long> pil;
typedef vector<pair<int, int>> vii;
typedef vector<pair<long long, long long>> vll;
typedef vector<pair<long long, int>> vli;
typedef vector<pair<int, long long>> vil;

template <class T1, class T2>
bool maximize(T1 &x, T2 y) {
    if (x < y) {
        x = y;
        return true;
    }
    return false;
}
template <class T1, class T2>
bool minimize(T1 &x, T2 y) {
    if (x > y) {
        x = y;
        return true;
    }
    return false;
}

template <class T>
void remove_duplicate(vector<T> &ve) {
    sort (ve.begin(), ve.end());
    ve.resize(unique(ve.begin(), ve.end()) - ve.begin());
}

mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
template <class T> T random(T l, T r) {
    return uniform_int_distribution<T>(l, r)(rng);
}
template <class T> T random(T r) {
    return rng() % r;
}

const int N = 2e5 + 5, K = 1e6 + 5;
const int MOD = 1e9 + 7;
const int inf = 1e9;
const ll INF = 1e18;

int n, k, ans = inf;
int sz[N], f[K];
vector<int> all_lengths;
vii adj[N];
bitset<N> deleted;

void count_child(int u, int fa) {
    sz[u] = 1;
    for (auto it : adj[u]) {
        int v = it.fi;
        if (v != fa && !deleted[v]) {
            count_child(v, u);
            sz[u] += sz[v];
        }
    }
}

int get_centroid(const int n, int u, int fa) {
    for (auto it : adj[u]) {
        int v = it.fi;
        if (v != fa && !deleted[v] && 2 * sz[v] > n) return get_centroid(n, v, u);
    }
    return u;
}

void dfs(int u, int fa, int depth, int length, bool update) {
    if (length > k) return;
    if (update) {
        minimize(f[length], depth);
        all_lengths.emplace_back(length);
    }
    else minimize(ans, depth + f[k - length]);
    for (auto it : adj[u]) {
        int v = it.fi, w = it.se;
        if (v != fa && !deleted[v]) dfs(v, u, depth + 1, length + w, update);
    }
}

void centroid_decomp(int u) {
    count_child(u, -1); int centroid = get_centroid(sz[u], u, -1);
    deleted[centroid] = true;

    all_lengths.clear(); f[0] = 0;
    for (auto it : adj[u]) {
        int v = it.fi, w = it.se;
        if (!deleted[v]) {
            dfs(v, u, 1, w, false);
            dfs(v, u, 1, w, true);
        }
    }

    for (auto length : all_lengths) f[length] = inf;

    for (auto it : adj[u]) if (!deleted[it.fi]) {
        centroid_decomp(it.fi);
    }
}

int best_path(int _n, int _k, int H[][2], int L[]) {
    n = _n, k = _k;
    for (int i = 0; i < n - 1; ++i) {
        int u = H[i][0], v = H[i][1], w = L[i];
        adj[u].emplace_back(v, w),
        adj[v].emplace_back(u, w);
    }

    ans = inf; centroid_decomp(1);
    return ans;
}

#ifdef hwe
signed main() {
    ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
    
    

    cerr << '\n'; return 0;
}
#endif

• Subtask 1: 0 / 9
• Subtask 2: 0 / 12
• Subtask 3: 0 / 22
• Subtask 4: 0 / 57