oj.uz

답안 #375899

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
375899 2021-03-10T08:31:42 Z topovik Papričice (COCI20_papricice) C++14
110 / 110
 345 ms 21740 KB 
#include <bits/stdc++.h>
#define f first
#define s second
#define pb push_back
#define len(x) x.size()
#define debug(x) cout << #x << " is " << x << endl

using namespace std;

typedef long long ll;
typedef long double ld;

const ll N = 1e6 + 100;
const ll oo = 1e9 + 7;

set <int> anc;
set <int> not_anc;
set<int> :: iterator mn, mx;

vector <vector <int> > a;

int sz[N];
int n;
int ans = oo;

int calc_sz(int x, int y)
{
    sz[x] = 1;
    for (int i = 0; i < len(a[x]); i++)
        if (a[x][i] != y) sz[x] += calc_sz(a[x][i], x);
    return sz[x];
}

void update(int x, int y, int z)
{
    ans = min(ans, max(max(x, y), z) - min(min(x, y), z));
}

void Check(int x)
{
    if (!anc.empty())
    {
        mn = anc.lower_bound((n + sz[x]) / 2);
        if (mn != anc.end()) update(sz[x], *mn - sz[x], n - *mn);
        if (mn != anc.begin())
        {
            mn--;
            update(sz[x], *mn - sz[x], n - *mn);
        }
    }
    if (!not_anc.empty())
    {
        mn = not_anc.lower_bound((n - sz[x]) / 2);
        mx = not_anc.end();
        if (mn != not_anc.begin() && !not_anc.empty()) {mx = --mn; mn++;}
        if (mn != not_anc.end()) update(sz[x], *mn, n - sz[x] - *mn);
        if (mx != not_anc.end()) update(sz[x], *mx, n - sz[x] - *mx);
    }
}

void Rec(int x, int y)
{
    Check(x);
    anc.insert(sz[x]);
    for (int i = 0; i < len(a[x]); i++)
        if (a[x][i] != y) Rec(a[x][i], x);
    not_anc.insert(sz[x]);
    anc.erase(sz[x]);
}

int main()
{
    cin >> n;
    a.resize(n);
    for (int i = 0; i < n - 1; i++)
    {
        int x, y;
        cin >> x >> y;
        a[--x].pb(--y);
        a[y].pb(x);
    }
    calc_sz(0, 0);
    Rec(0, 0);
    cout << ans;
}

Compilation message

papricice.cpp: In function 'int calc_sz(int, int)':
papricice.cpp:29:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   29 |     for (int i = 0; i < len(a[x]); i++)
      |                       ^
papricice.cpp: In function 'void Rec(int, int)':
papricice.cpp:65:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   65 |     for (int i = 0; i < len(a[x]); i++)
      |                       ^

Subtask #1
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 364 KB Output is correct
2 Correct 1 ms 364 KB Output is correct
3 Correct 1 ms 364 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 1 ms 364 KB Output is correct

Subtask #2
35.0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 364 KB Output is correct
2 Correct 1 ms 364 KB Output is correct
3 Correct 1 ms 364 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 1 ms 364 KB Output is correct
6 Correct 2 ms 492 KB Output is correct
7 Correct 3 ms 492 KB Output is correct
8 Correct 2 ms 492 KB Output is correct
9 Correct 2 ms 492 KB Output is correct
10 Correct 2 ms 492 KB Output is correct

Subtask #3
60.0 / 60.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 364 KB Output is correct
2 Correct 1 ms 364 KB Output is correct
3 Correct 1 ms 364 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 1 ms 364 KB Output is correct
6 Correct 2 ms 492 KB Output is correct
7 Correct 3 ms 492 KB Output is correct
8 Correct 2 ms 492 KB Output is correct
9 Correct 2 ms 492 KB Output is correct
10 Correct 2 ms 492 KB Output is correct
11 Correct 317 ms 12268 KB Output is correct
12 Correct 330 ms 14828 KB Output is correct
13 Correct 309 ms 15588 KB Output is correct
14 Correct 290 ms 14956 KB Output is correct
15 Correct 345 ms 14700 KB Output is correct
16 Correct 207 ms 14568 KB Output is correct
17 Correct 294 ms 14776 KB Output is correct
18 Correct 322 ms 21740 KB Output is correct
19 Correct 331 ms 14980 KB Output is correct
20 Correct 304 ms 14956 KB Output is correct