oj.uz

답안 #359944

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
359944 2021-01-27T10:50:11 Z MrRobot_28 Papričice (COCI20_papricice) C++17
15 / 110
 6 ms 5228 KB 
#include<bits/stdc++.h>
using namespace std;
set <pair <int, int> > st, st1;
const int N = 2e5;
vector <int> g[N];
int _sz[N];
void build(int v, int p = -1)
{
    _sz[v] = 1;
    for(int i = 0; i < g[v].size(); i++)
    {
        int to = g[v][i];
        if(to != p)
        {
            build(to, v);
            _sz[v] += _sz[to];
        }
    }
}
int n;
int ans = 1e9;
void funct(int a, int b, int c)
{
        int t = max(abs(a - b), max(abs(b - c), abs(a - c)));
        ans = min(ans, t);
}
void dfs(int v, int p = -1)
{
    st.insert({n - _sz[v], v});
    for(int i = 0; i < g[v].size(); i++)
    {
        int to = g[v][i];
        if(to != p)
        {
            dfs(to, v);
        }
    }
    st.erase({n - _sz[v], v});
    int sz1 = (n - _sz[v]) / 2;
    set <pair <int, int> > :: iterator it1, it2;
    it1 = st.lower_bound({sz1, 0});
    it2 = st1.lower_bound({sz1, 0});
    if(it1 != st.end())
    {
        int a = _sz[v];
        int b = it1 -> first;
        int c = n - a - b;
        funct(a, b,c);
    }
    if(it1 != st.begin())
    {
        it1--;
        int a = _sz[v];
        int b = it1 -> first;
        int c = n - a - b;
        funct(a, b,c);
    }
    if(it2 != st1.end())
    {
        int a = _sz[v];
        int b = it2 -> first;
        int c = n - a - b;
        funct(a, b, c);
    }
    if(it2 != st1.begin())
    {
        it2--;
        int a = _sz[v];
        int b = it2 -> first;
        int c = n - a - b;
        funct(a, b, c);
    }
    st1.insert({_sz[v], v});
}
signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cin >> n;
    for(int i = 0; i < n - 1; i++)
    {
        int a, b;
        cin >> a >> b;
        a--;
        b--;
        g[a].push_back(b);
        g[b].push_back(a);
    }
    build(0);
    dfs(0);
    cout << ans;
    return 0;
}

Compilation message

papricice.cpp: In function 'void build(int, int)':
papricice.cpp:10:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   10 |     for(int i = 0; i < g[v].size(); i++)
      |                    ~~^~~~~~~~~~~~~
papricice.cpp: In function 'void dfs(int, int)':
papricice.cpp:30:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 |     for(int i = 0; i < g[v].size(); i++)
      |                    ~~^~~~~~~~~~~~~

Subtask #1
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 5100 KB Output is correct
2 Correct 4 ms 5100 KB Output is correct
3 Correct 4 ms 5100 KB Output is correct
4 Correct 4 ms 5100 KB Output is correct
5 Correct 4 ms 5100 KB Output is correct

Subtask #2
0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 5100 KB Output is correct
2 Correct 4 ms 5100 KB Output is correct
3 Correct 4 ms 5100 KB Output is correct
4 Correct 4 ms 5100 KB Output is correct
5 Correct 4 ms 5100 KB Output is correct
6 Correct 6 ms 5228 KB Output is correct
7 Incorrect 5 ms 5228 KB Output isn't correct
8 Halted 0 ms 0 KB -

Subtask #3
0 / 60.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 5100 KB Output is correct
2 Correct 4 ms 5100 KB Output is correct
3 Correct 4 ms 5100 KB Output is correct
4 Correct 4 ms 5100 KB Output is correct
5 Correct 4 ms 5100 KB Output is correct
6 Correct 6 ms 5228 KB Output is correct
7 Incorrect 5 ms 5228 KB Output isn't correct
8 Halted 0 ms 0 KB -