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Submission #1061862

# Submission time Handle Problem Language Result Execution time Memory
1061862 2024-08-16T14:29:38 Z Ejen Mousetrap (CEOI17_mousetrap) C++14
100 / 100
 448 ms 170836 KB 
#include <bits/stdc++.h>
 
#define el '\n'
#define fu(i, a, b) for (long long i = a; i <= b; ++i)
#define fd(i, a, b) for (long long i = a; i >= b; --i)
#define ff first
#define ss second
#define all(v) v.begin(), v.end()
#define sz(v)  (ll)v.size()
#define mask(i) (1LL << i)
#define bit(x, i) ((x) >> (i) & 1)
 
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
 
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
 
ll Rand(ll l, ll r) {
    return uniform_int_distribution<ll> (l, r) (rng);
}
 
ll last(ll msk)    {return msk & (-msk);}
ll pop_cnt(ll msk) {return __builtin_popcountll(msk);}
ll ctz(ll msk)     {return __builtin_ctzll(msk);}
ll lg(ll msk)      {return 63 - __builtin_clzll(msk);}
 
template<class T1, class T2>
    bool maximize(T1 &a, T2 b) {
        if (a < b) {
            a = b;
            return true;
        }
        return false;
    }
 
template<class T1, class T2>
    bool minimize(T1 &a, T2 b) {
        if (a > b) {
            a = b;
            return true;
        }
        return false;
    }
 
template<class T>
    void print(T &a, string sep = " ", string stop = "\n") {
        for (auto x : a) cout << x << sep;
        cout << stop;
    }
 
template<class T>
    void compress(vector<T> &v) {
        sort(all(v));
        v.resize(unique(all(v)) - v.begin());
    }
 
const long long N = 1e6 + 27, base = 311, inf = 2e18, mod = 1e9 + 19972207;
 
ll n, t, m, timer;
ll a[N], f[N], par[N], del[N];
vector<ll> adj[N];
vector<pair<ll, ll>> save;

void update(ll &a, ll &b, ll c) {
    if (a < c) {
        b = a;
        a = c;
    }
    else maximize(b, c);
}
 
void dfs(ll u) {
    ll fi = 0, se = 0;
    f[u] = sz(adj[u]) - 1;
    if (u != t) del[u] = sz(adj[u]) - 2 + del[par[u]] + (u == m);
    for (ll v : adj[u]) {
        if (v == par[u]) continue;
        par[v] = u;
        dfs(v);
        update(fi, se, f[v]);
    }
    f[u] += se;
}
 
bool check(ll x) {
    ll block = 0;
    for (pair<ll, ll> tmp : save) {
        if (tmp.ss > x) {
            if (block + 1 > tmp.ff) return false;
            block++;
            x--;
        }
    }
    return x >= 0;
}

signed main() {
    // freopen("brentford40mu.inp", "r", stdin);
    // freopen("brentford40mu.out", "w", stdout);
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cin >> n >> t >> m;
    if (t == m) return cout << 0, 0;
    fu(i, 2, n) {
        ll u, v;
        cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    dfs(t);
    ll cnt = 0, pre = 0;
    while (t != m) {
        for (ll v : adj[m]) {
            if (v != par[m] && v != pre) save.push_back(make_pair(cnt + 1, f[v] + del[m]));
        }
        cnt++;
        pre = m;
        m = par[m];
    }
    // fu(i, 1, n) cout << del[i] << ' ';
    sort(all(save));
    // cout << el;
    // for (pair<ll, ll> tmp : save) cout << tmp.ff << ' ' << tmp.ss << el;
    ll l = 0, r = 2 * n;
    while (l < r) {
        ll mid = (l + r) / 2;
        if (check(mid)) r = mid;
        else l = mid + 1;
    }
    cout << l;
}

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 27224 KB Output is correct
2 Correct 5 ms 27228 KB Output is correct
3 Correct 4 ms 27228 KB Output is correct
4 Correct 5 ms 27224 KB Output is correct
5 Correct 4 ms 27228 KB Output is correct
6 Correct 4 ms 27228 KB Output is correct
7 Correct 4 ms 27228 KB Output is correct
8 Correct 4 ms 27228 KB Output is correct
9 Correct 4 ms 27228 KB Output is correct
10 Correct 4 ms 27228 KB Output is correct

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 171 ms 86864 KB Output is correct
2 Correct 169 ms 82636 KB Output is correct
3 Correct 448 ms 85072 KB Output is correct
4 Correct 171 ms 59988 KB Output is correct
5 Correct 417 ms 85076 KB Output is correct
6 Correct 404 ms 85072 KB Output is correct

Subtask #3
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 27224 KB Output is correct
2 Correct 5 ms 27228 KB Output is correct
3 Correct 4 ms 27228 KB Output is correct
4 Correct 5 ms 27224 KB Output is correct
5 Correct 4 ms 27228 KB Output is correct
6 Correct 4 ms 27228 KB Output is correct
7 Correct 4 ms 27228 KB Output is correct
8 Correct 4 ms 27228 KB Output is correct
9 Correct 4 ms 27228 KB Output is correct
10 Correct 4 ms 27228 KB Output is correct
11 Correct 4 ms 27228 KB Output is correct
12 Correct 4 ms 27228 KB Output is correct
13 Correct 4 ms 27228 KB Output is correct
14 Correct 5 ms 27228 KB Output is correct
15 Correct 4 ms 27228 KB Output is correct
16 Correct 5 ms 27228 KB Output is correct
17 Correct 4 ms 27228 KB Output is correct
18 Correct 4 ms 27276 KB Output is correct
19 Correct 7 ms 27484 KB Output is correct
20 Correct 5 ms 27312 KB Output is correct
21 Correct 4 ms 27388 KB Output is correct
22 Correct 4 ms 27228 KB Output is correct

Subtask #4
35.0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 27224 KB Output is correct
2 Correct 5 ms 27228 KB Output is correct
3 Correct 4 ms 27228 KB Output is correct
4 Correct 5 ms 27224 KB Output is correct
5 Correct 4 ms 27228 KB Output is correct
6 Correct 4 ms 27228 KB Output is correct
7 Correct 4 ms 27228 KB Output is correct
8 Correct 4 ms 27228 KB Output is correct
9 Correct 4 ms 27228 KB Output is correct
10 Correct 4 ms 27228 KB Output is correct
11 Correct 171 ms 86864 KB Output is correct
12 Correct 169 ms 82636 KB Output is correct
13 Correct 448 ms 85072 KB Output is correct
14 Correct 171 ms 59988 KB Output is correct
15 Correct 417 ms 85076 KB Output is correct
16 Correct 404 ms 85072 KB Output is correct
17 Correct 4 ms 27228 KB Output is correct
18 Correct 4 ms 27228 KB Output is correct
19 Correct 4 ms 27228 KB Output is correct
20 Correct 5 ms 27228 KB Output is correct
21 Correct 4 ms 27228 KB Output is correct
22 Correct 5 ms 27228 KB Output is correct
23 Correct 4 ms 27228 KB Output is correct
24 Correct 4 ms 27276 KB Output is correct
25 Correct 7 ms 27484 KB Output is correct
26 Correct 5 ms 27312 KB Output is correct
27 Correct 4 ms 27388 KB Output is correct
28 Correct 4 ms 27228 KB Output is correct
29 Correct 4 ms 27228 KB Output is correct
30 Correct 192 ms 100212 KB Output is correct
31 Correct 180 ms 100180 KB Output is correct
32 Correct 223 ms 170836 KB Output is correct
33 Correct 229 ms 170836 KB Output is correct
34 Correct 412 ms 98388 KB Output is correct
35 Correct 415 ms 98388 KB Output is correct
36 Correct 421 ms 111796 KB Output is correct
37 Correct 414 ms 111812 KB Output is correct
38 Correct 318 ms 112844 KB Output is correct
39 Correct 327 ms 112848 KB Output is correct
40 Correct 353 ms 112848 KB Output is correct