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Submission #1016163

# Submission time Handle Problem Language Result Execution time Memory
1016163 2024-07-07T13:03:27 Z vjudge1 Papričice (COCI20_papricice) C++17
110 / 110
 171 ms 19912 KB 
#include <bits/stdc++.h>
using namespace std;

const int N = 2e5 + 10;
int n, sz[N], ans = 1e9;
vector<int> g[N];

void pre_dfs(int v, int p = -1){
    sz[v] = 1;
    for (int u : g[v]){
        if (u == p) continue;
        pre_dfs(u, v);
        sz[v] += sz[u];
    }
}

set<int> anc, non_anc;

void dfs(int v, int p = -1){
    auto lb = anc.lower_bound(sz[v] + (n - sz[v]) / 2);
    if (lb != anc.end()){
        int mx = max({sz[v], (*lb) - sz[v], n - (*lb)});
        int mn = min({sz[v], (*lb) - sz[v], n - (*lb)});
        ans = min(ans, mx - mn);
    }
    if (lb != anc.begin()){
        lb--;
        int mx = max({sz[v], (*lb) - sz[v], n - (*lb)});
        int mn = min({sz[v], (*lb) - sz[v], n - (*lb)});
        ans = min(ans, mx - mn);
    }

    lb = anc.lower_bound(sz[v] + (n - sz[v]) / 2 + 1);
    if (lb != anc.end()){
        int mx = max({sz[v], (*lb) - sz[v], n - (*lb)});
        int mn = min({sz[v], (*lb) - sz[v], n - (*lb)});
        ans = min(ans, mx - mn);
    }
    if (lb != anc.begin()){
        lb--;
        int mx = max({sz[v], (*lb) - sz[v], n - (*lb)});
        int mn = min({sz[v], (*lb) - sz[v], n - (*lb)});
        ans = min(ans, mx - mn);
    }

    auto it = non_anc.lower_bound((n - sz[v]) / 2);
    if (it != non_anc.end()){
        int mx = max({sz[v], (*it), n - (*it) - sz[v]});
        int mn = min({sz[v], (*it), n - (*it) - sz[v]});
        ans = min(ans, mx - mn);
    }
    if (it != non_anc.begin()){
        it--;
        int mx = max({sz[v], (*it), n - (*it) - sz[v]});
        int mn = min({sz[v], (*it), n - (*it) - sz[v]});
        ans = min(ans, mx - mn);
    }

    it = non_anc.lower_bound((n - sz[v]) / 2 + 1);
    if (it != non_anc.end()){
        int mx = max({sz[v], (*it), n - (*it) - sz[v]});
        int mn = min({sz[v], (*it), n - (*it) - sz[v]});
        ans = min(ans, mx - mn);
    }
    if (it != non_anc.begin()){
        it--;
        int mx = max({sz[v], (*it), n - (*it) - sz[v]});
        int mn = min({sz[v], (*it), n - (*it) - sz[v]});
        ans = min(ans, mx - mn);
    }

    anc.insert(sz[v]);
    for (int u : g[v]){
        if (u == p) continue;
        dfs(u, v);
    }
    anc.erase(sz[v]);
    non_anc.insert(sz[v]);
}

int main(){
    cin >> n;
    for (int i = 1; i < n; i ++){
        int u, v;
        cin >> u >> v;
        
        g[u].push_back(v);
        g[v].push_back(u);
    }

    pre_dfs(1);
    dfs(1);

    cout << ans << endl;
}

Subtask #1
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4952 KB Output is correct
2 Correct 2 ms 4956 KB Output is correct
3 Correct 2 ms 4968 KB Output is correct
4 Correct 2 ms 4956 KB Output is correct
5 Correct 2 ms 4956 KB Output is correct

Subtask #2
35.0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4952 KB Output is correct
2 Correct 2 ms 4956 KB Output is correct
3 Correct 2 ms 4968 KB Output is correct
4 Correct 2 ms 4956 KB Output is correct
5 Correct 2 ms 4956 KB Output is correct
6 Correct 3 ms 5212 KB Output is correct
7 Correct 2 ms 5212 KB Output is correct
8 Correct 3 ms 5212 KB Output is correct
9 Correct 3 ms 5012 KB Output is correct
10 Correct 3 ms 5212 KB Output is correct

Subtask #3
60.0 / 60.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4952 KB Output is correct
2 Correct 2 ms 4956 KB Output is correct
3 Correct 2 ms 4968 KB Output is correct
4 Correct 2 ms 4956 KB Output is correct
5 Correct 2 ms 4956 KB Output is correct
6 Correct 3 ms 5212 KB Output is correct
7 Correct 2 ms 5212 KB Output is correct
8 Correct 3 ms 5212 KB Output is correct
9 Correct 3 ms 5012 KB Output is correct
10 Correct 3 ms 5212 KB Output is correct
11 Correct 143 ms 12244 KB Output is correct
12 Correct 119 ms 12116 KB Output is correct
13 Correct 145 ms 12884 KB Output is correct
14 Correct 125 ms 12404 KB Output is correct
15 Correct 123 ms 12372 KB Output is correct
16 Correct 83 ms 13008 KB Output is correct
17 Correct 126 ms 12292 KB Output is correct
18 Correct 171 ms 19912 KB Output is correct
19 Correct 118 ms 12504 KB Output is correct
20 Correct 137 ms 12344 KB Output is correct