oj.uz

Submission #705594

# Submission time Handle Problem Language Result Execution time Memory
705594 2023-03-04T17:59:13 Z Kahou Mousetrap (CEOI17_mousetrap) C++14
40 / 100
 5000 ms 72044 KB 
#include<bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define endl '\n'
#define mk make_pair
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int N = 1e6 + 50;
ll n, t, m, val[N], dp[N], ps[N], k; 
bool mark[N];
vector<int> adj[N];
vector<int> vp;
vector<pii> vc;

void dfs(int u, int p=0) {
        cerr << "YES " << u << endl;
        if (u == t) return;
        int mx1 = 0, mx2 = 0;
        for (int v:adj[u]) {
                if (v == p) continue;
                dfs(v, u);
                if (mark[v]) {
                        mark[u] = 1;
                        val[u] = val[v] + (int)adj[u].size()-1-(p>0);
                }
                else {
                        if (dp[v] > mx1) {
                                mx2 = mx1;
                                mx1 = dp[v];
                        }
                        else if (dp[v] > mx2) {
                                mx2 = dp[v];
                        }
                }
        }
        cerr << "OK " << endl;
        if (!mark[u]) {
                dp[u] = (int)adj[u].size()-(p>0) + mx2;
        }
        else {
                vp.push_back(u);
                for (int v:adj[u]) {
                        if (v == p) continue;
                        if (mark[v]) continue;
                        vc.push_back({u, dp[v] + val[u]});
                }
        }
        cerr << "OK " << endl;
}

bool isval(ll x) {
        int id = 0;
        int tmp = 0;
        for (pii p:vc) {
                while (id < p.F) {
                        ps[id+1] = ps[id];
                        tmp = ps[id];
                        id++;
                }
                if (tmp+p.S > x) {
                        ps[id]++;
                }
        }
        for (int i = 1; i <= k; i++) {
                if (ps[i] > i || ps[i] > x) return 0;
        }
        return 1;
}
void solve() {
        cin >> n >> t >> m;
        for (int i = 1; i <= n-1; i++) {
                int u, v;
                cin >> u >> v;
                adj[u].push_back(v);
                adj[v].push_back(u);
        }
        mark[t] = 1;
        dfs(m);
        cerr << "OK " << endl;
        reverse(vp.begin(), vp.end());
        reverse(vc.begin(), vc.end());
        for (pii &x : vc) {
                if (x.F != vp[k]) k++;
                x.F = k+1;
        }
        k = vp.size();
        ll dw = -1, up = 1e9;
        while (up-dw > 1) {
                ll md = (up+dw)>>1;
                if (isval(md)) up = md;
                else dw = md;
        }
        cout << up << endl;
}

int main() {
        ios::sync_with_stdio(0), cin.tie(0);
        solve();
        return 0;
}

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 23764 KB Output is correct
2 Correct 11 ms 23764 KB Output is correct
3 Correct 12 ms 23740 KB Output is correct
4 Correct 12 ms 23764 KB Output is correct
5 Correct 12 ms 23764 KB Output is correct
6 Correct 13 ms 23728 KB Output is correct
7 Correct 13 ms 23728 KB Output is correct
8 Correct 13 ms 23716 KB Output is correct
9 Correct 13 ms 23764 KB Output is correct
10 Correct 14 ms 23764 KB Output is correct

Subtask #2
0 / 25.0

# Verdict Execution time Memory Grader output
1 Execution timed out 5016 ms 72044 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #3
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 23764 KB Output is correct
2 Correct 11 ms 23764 KB Output is correct
3 Correct 12 ms 23740 KB Output is correct
4 Correct 12 ms 23764 KB Output is correct
5 Correct 12 ms 23764 KB Output is correct
6 Correct 13 ms 23728 KB Output is correct
7 Correct 13 ms 23728 KB Output is correct
8 Correct 13 ms 23716 KB Output is correct
9 Correct 13 ms 23764 KB Output is correct
10 Correct 14 ms 23764 KB Output is correct
11 Correct 11 ms 23764 KB Output is correct
12 Correct 20 ms 23884 KB Output is correct
13 Correct 19 ms 23880 KB Output is correct
14 Correct 21 ms 23964 KB Output is correct
15 Correct 19 ms 23968 KB Output is correct
16 Correct 20 ms 23880 KB Output is correct
17 Correct 20 ms 23892 KB Output is correct
18 Correct 23 ms 23884 KB Output is correct
19 Correct 19 ms 23892 KB Output is correct
20 Correct 19 ms 23896 KB Output is correct
21 Correct 20 ms 23892 KB Output is correct
22 Correct 17 ms 23764 KB Output is correct

Subtask #4
0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 23764 KB Output is correct
2 Correct 11 ms 23764 KB Output is correct
3 Correct 12 ms 23740 KB Output is correct
4 Correct 12 ms 23764 KB Output is correct
5 Correct 12 ms 23764 KB Output is correct
6 Correct 13 ms 23728 KB Output is correct
7 Correct 13 ms 23728 KB Output is correct
8 Correct 13 ms 23716 KB Output is correct
9 Correct 13 ms 23764 KB Output is correct
10 Correct 14 ms 23764 KB Output is correct
11 Execution timed out 5016 ms 72044 KB Time limit exceeded
12 Halted 0 ms 0 KB -