oj.uz

Submission #1110933

# Submission time Handle Problem Language Result Execution time Memory
1110933 2024-11-11T03:24:32 Z haianhnguyen08102007 Mousetrap (CEOI17_mousetrap) C++17
100 / 100
 537 ms 162648 KB 
#include <bits/stdc++.h>
#define int long long
#define ll long long
#define fi first
#define se second
#define pb push_back
#define pii pair<int, int>

#define sz(v) (int)(v).size()
#define all(v) (v).begin(), (v).end()
#define rall(v) (v).rbegin(), (v).rend()
#define foru(i,a,b) for(int i = (a); i <= (b); ++i)
#define ford(i,a,b) for(int i = (a); i >= (b); --i)

template<typename T> bool maximize(T &res, const T &val) { if (res < val) { res = val; return true; } return false; }
template<typename T> bool minimize(T &res, const T &val) { if (val < res) { res = val; return true; } return false; }

using namespace std;

const int N = 1e6 + 5;
const int inf = 1e18;

vector <int> adj[N];
int n, t, m, dp[N], par[N];

void dfs(int pos, int prev)
{
    if (prev != -1)
        adj[pos].erase(find(adj[pos].begin(), adj[pos].end(), prev));
    int mx = 0, sc = 0;
    for (auto x : adj[pos])
    {
        par[x] = pos;
        dfs(x, pos);
        if (dp[x] >= mx) sc = mx, mx = dp[x];
        else sc = max(sc, dp[x]);
    }
    dp[pos] = sc + adj[pos].size();
}

int32_t main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);

    cin>>n>>t>>m;
    t--; m--;
    for (int i=0; i<n-1; i++)
    {
        int a, b; cin>>a>>b;
        a--; b--;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }

    dfs(t, -1);
    int ttld = 0, l = -1, r = n;
    while (l + 1 < r)
    {
        int mid = (l+r)/2, ok = 1, dif = 0, prev = -1, canuse = 0, cur = m, used = 0;
        while (cur != t)
        {
            canuse++; int tmp = 0;
            for (auto x:adj[cur])
            {
                if (x==prev) continue;
                if (dp[x] - dif + used > mid)
                {
                    if (!canuse) ok = 0;
                    else canuse--, tmp++;
                }
            }
            used += tmp, dif += adj[cur].size() - (prev != -1);
            prev = cur, cur = par[cur];
        }
        ttld = dif;
        if (ok) r = mid;
        else l = mid;
    }

    cout<<r + ttld;

    return 0;
}

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 26960 KB Output is correct
2 Correct 6 ms 26960 KB Output is correct
3 Correct 5 ms 26960 KB Output is correct
4 Correct 6 ms 26960 KB Output is correct
5 Correct 5 ms 26960 KB Output is correct
6 Correct 6 ms 26960 KB Output is correct
7 Correct 5 ms 26960 KB Output is correct
8 Correct 5 ms 26960 KB Output is correct
9 Correct 5 ms 27104 KB Output is correct
10 Correct 6 ms 26960 KB Output is correct

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 201 ms 91924 KB Output is correct
2 Correct 181 ms 86600 KB Output is correct
3 Correct 471 ms 90184 KB Output is correct
4 Correct 223 ms 60488 KB Output is correct
5 Correct 528 ms 90184 KB Output is correct
6 Correct 537 ms 90220 KB Output is correct

Subtask #3
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 26960 KB Output is correct
2 Correct 6 ms 26960 KB Output is correct
3 Correct 5 ms 26960 KB Output is correct
4 Correct 6 ms 26960 KB Output is correct
5 Correct 5 ms 26960 KB Output is correct
6 Correct 6 ms 26960 KB Output is correct
7 Correct 5 ms 26960 KB Output is correct
8 Correct 5 ms 26960 KB Output is correct
9 Correct 5 ms 27104 KB Output is correct
10 Correct 6 ms 26960 KB Output is correct
11 Correct 6 ms 26960 KB Output is correct
12 Correct 7 ms 26960 KB Output is correct
13 Correct 6 ms 26960 KB Output is correct
14 Correct 9 ms 27216 KB Output is correct
15 Correct 6 ms 27216 KB Output is correct
16 Correct 6 ms 26964 KB Output is correct
17 Correct 6 ms 26960 KB Output is correct
18 Correct 6 ms 27108 KB Output is correct
19 Correct 6 ms 26960 KB Output is correct
20 Correct 7 ms 26960 KB Output is correct
21 Correct 6 ms 26960 KB Output is correct
22 Correct 8 ms 26960 KB Output is correct

Subtask #4
35.0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 26960 KB Output is correct
2 Correct 6 ms 26960 KB Output is correct
3 Correct 5 ms 26960 KB Output is correct
4 Correct 6 ms 26960 KB Output is correct
5 Correct 5 ms 26960 KB Output is correct
6 Correct 6 ms 26960 KB Output is correct
7 Correct 5 ms 26960 KB Output is correct
8 Correct 5 ms 26960 KB Output is correct
9 Correct 5 ms 27104 KB Output is correct
10 Correct 6 ms 26960 KB Output is correct
11 Correct 201 ms 91924 KB Output is correct
12 Correct 181 ms 86600 KB Output is correct
13 Correct 471 ms 90184 KB Output is correct
14 Correct 223 ms 60488 KB Output is correct
15 Correct 528 ms 90184 KB Output is correct
16 Correct 537 ms 90220 KB Output is correct
17 Correct 6 ms 26960 KB Output is correct
18 Correct 7 ms 26960 KB Output is correct
19 Correct 6 ms 26960 KB Output is correct
20 Correct 9 ms 27216 KB Output is correct
21 Correct 6 ms 27216 KB Output is correct
22 Correct 6 ms 26964 KB Output is correct
23 Correct 6 ms 26960 KB Output is correct
24 Correct 6 ms 27108 KB Output is correct
25 Correct 6 ms 26960 KB Output is correct
26 Correct 7 ms 26960 KB Output is correct
27 Correct 6 ms 26960 KB Output is correct
28 Correct 8 ms 26960 KB Output is correct
29 Correct 6 ms 26976 KB Output is correct
30 Correct 206 ms 92100 KB Output is correct
31 Correct 197 ms 91968 KB Output is correct
32 Correct 339 ms 162488 KB Output is correct
33 Correct 300 ms 162648 KB Output is correct
34 Correct 470 ms 90184 KB Output is correct
35 Correct 479 ms 90052 KB Output is correct
36 Correct 526 ms 97864 KB Output is correct
37 Correct 471 ms 97864 KB Output is correct
38 Correct 420 ms 102216 KB Output is correct
39 Correct 405 ms 102496 KB Output is correct
40 Correct 399 ms 102216 KB Output is correct