oj.uz

Submission #596782

# Submission time Handle Problem Language Result Execution time Memory
596782 2022-07-15T04:46:10 Z 1bin Mousetrap (CEOI17_mousetrap) C++14
100 / 100
 864 ms 166320 KB 
#include <bits/stdc++.h>

using namespace std;

#define all(v) v.begin(), v.end()
typedef long long ll;
const int NMAX = 1e6 + 5;
int n, t, m, u, v, d, dp[NMAX], inP[NMAX];
vector<int> adj[NMAX], P;

int dfs(int x, int p){
    int ret = x == m;
    for(int nx : adj[x]){
        if(nx == p) continue;
        ret |= dfs(nx, x);
    }
    if(ret) P.emplace_back(x), inP[x] = 1;
    return ret;
}

void dfs2(int x, int p){
    int deg, mx1, mx2, t;
    deg = mx1 = mx2 = 0;
    
    for(int nx : adj[x]){
        if(nx == p) continue;
        dfs2(nx, x); deg++;
        t = dp[nx];
        if(t > mx2) mx2 = t;
        if(mx2 > mx1) swap(mx1, mx2);
    }
    dp[x] = mx2 + deg;
    return;
}

int go(int m){
    int cnt = 0, b = 0, deg = d;
    
    for(int p : P){
        int t = 0; cnt++;
        for(int x: adj[p]) {
            if(inP[x]) continue;
            if(dp[x] + deg > m) b++;
            else t++;
        }
        if(b > cnt) return 0;
        deg -= t;
    }
    return 1;
}

int main(void){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    
    cin >> n >> t >> m;
    for(int i = 0; i < n - 1; i++){
        cin >> u >> v;
        adj[u].emplace_back(v);
        adj[v].emplace_back(u);
    }
    
    dfs(t, -1); P.pop_back();
    for(int p : P)
        for(int x : adj[p]) 
            if(!inP[x]) dfs2(x, p), d++;
    
    int l = d, r = 2 * n;
    while(l < r){
        int m = (l + r) >> 1;
        if(go(m)) r = m;
        else l = m + 1;
    }
    cout << l;
    return 0;
}

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 23764 KB Output is correct
2 Correct 13 ms 23728 KB Output is correct
3 Correct 13 ms 23756 KB Output is correct
4 Correct 13 ms 23812 KB Output is correct
5 Correct 13 ms 23764 KB Output is correct
6 Correct 12 ms 23812 KB Output is correct
7 Correct 12 ms 23788 KB Output is correct
8 Correct 12 ms 23764 KB Output is correct
9 Correct 12 ms 23764 KB Output is correct
10 Correct 12 ms 23764 KB Output is correct

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 322 ms 72316 KB Output is correct
2 Correct 244 ms 67472 KB Output is correct
3 Correct 789 ms 73304 KB Output is correct
4 Correct 346 ms 48440 KB Output is correct
5 Correct 847 ms 73368 KB Output is correct
6 Correct 756 ms 73268 KB Output is correct

Subtask #3
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 23764 KB Output is correct
2 Correct 13 ms 23728 KB Output is correct
3 Correct 13 ms 23756 KB Output is correct
4 Correct 13 ms 23812 KB Output is correct
5 Correct 13 ms 23764 KB Output is correct
6 Correct 12 ms 23812 KB Output is correct
7 Correct 12 ms 23788 KB Output is correct
8 Correct 12 ms 23764 KB Output is correct
9 Correct 12 ms 23764 KB Output is correct
10 Correct 12 ms 23764 KB Output is correct
11 Correct 14 ms 23816 KB Output is correct
12 Correct 13 ms 23776 KB Output is correct
13 Correct 12 ms 23764 KB Output is correct
14 Correct 13 ms 23892 KB Output is correct
15 Correct 13 ms 23892 KB Output is correct
16 Correct 14 ms 23764 KB Output is correct
17 Correct 15 ms 23772 KB Output is correct
18 Correct 13 ms 23764 KB Output is correct
19 Correct 14 ms 23824 KB Output is correct
20 Correct 13 ms 23856 KB Output is correct
21 Correct 13 ms 23816 KB Output is correct
22 Correct 12 ms 23844 KB Output is correct

Subtask #4
35.0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 23764 KB Output is correct
2 Correct 13 ms 23728 KB Output is correct
3 Correct 13 ms 23756 KB Output is correct
4 Correct 13 ms 23812 KB Output is correct
5 Correct 13 ms 23764 KB Output is correct
6 Correct 12 ms 23812 KB Output is correct
7 Correct 12 ms 23788 KB Output is correct
8 Correct 12 ms 23764 KB Output is correct
9 Correct 12 ms 23764 KB Output is correct
10 Correct 12 ms 23764 KB Output is correct
11 Correct 322 ms 72316 KB Output is correct
12 Correct 244 ms 67472 KB Output is correct
13 Correct 789 ms 73304 KB Output is correct
14 Correct 346 ms 48440 KB Output is correct
15 Correct 847 ms 73368 KB Output is correct
16 Correct 756 ms 73268 KB Output is correct
17 Correct 14 ms 23816 KB Output is correct
18 Correct 13 ms 23776 KB Output is correct
19 Correct 12 ms 23764 KB Output is correct
20 Correct 13 ms 23892 KB Output is correct
21 Correct 13 ms 23892 KB Output is correct
22 Correct 14 ms 23764 KB Output is correct
23 Correct 15 ms 23772 KB Output is correct
24 Correct 13 ms 23764 KB Output is correct
25 Correct 14 ms 23824 KB Output is correct
26 Correct 13 ms 23856 KB Output is correct
27 Correct 13 ms 23816 KB Output is correct
28 Correct 12 ms 23844 KB Output is correct
29 Correct 14 ms 23764 KB Output is correct
30 Correct 277 ms 72392 KB Output is correct
31 Correct 289 ms 72324 KB Output is correct
32 Correct 374 ms 139028 KB Output is correct
33 Correct 346 ms 166320 KB Output is correct
34 Correct 828 ms 73336 KB Output is correct
35 Correct 831 ms 73364 KB Output is correct
36 Correct 864 ms 80088 KB Output is correct
37 Correct 857 ms 80032 KB Output is correct
38 Correct 557 ms 82740 KB Output is correct
39 Correct 641 ms 82788 KB Output is correct
40 Correct 655 ms 82736 KB Output is correct