제출 #980769

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
980769		davitmarg	서열 (APIO23_sequence)	C++17	28 / 100	2071 ms	48768 KiB

sequence

#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <algorithm>
#include <cmath>
#include <vector>
#include <string>
#include <cstring>
#include <map>
#include <unordered_map>
#include <set>
#include <unordered_set>
#include <queue>
#include <bitset>
#include <stack>
#include <cassert>
#include <iterator>
#include <random>
#include <chrono>
#include <fstream>
#define fastIO                   \
    ios::sync_with_stdio(false); \
    cin.tie(0);                  \
    cout.tie(0);
#define mod 1000000007ll
#define LL long long
#define LD long double
#define MP make_pair
#define PB push_back
#define all(v) v.begin(), v.end()
using namespace std;

const int N = 500005;

int n, a[N], ans;
vector<int> pos[N];
pair<int, int> t[N * 4];
int d[N * 4];

pair<int, int> merge(pair<int, int> a, pair<int, int> b)
{
    return MP(min(a.first, b.first), max(a.second, b.second));
}

void build(int v,int l,int r)
{
    t[v] = MP(0, 0);
    d[v] = 0;
    if (l == r)
        return;
    int m = (l + r) / 2;
    build(v * 2, l, m);
    build(v * 2 + 1, m + 1, r);
}

void push(int v, int l, int r)
{
    if (d[v] == 0)
        return;
    if (l != r)
    {
        d[v * 2] += d[v];
        d[v * 2 + 1] += d[v];
    }
    t[v] = MP(t[v].first + d[v], t[v].second + d[v]);
    d[v] = 0;
}

void add(int v, int l, int r, int i, int j, int val)
{
    push(v, l, r);
    if (i > j)
        return;
    if (i == l && j == r)
    {
        d[v] += val;
        push(v, l, r);
        return;
    }

    int m = (l + r) / 2;
    add(v * 2, l, m, i, min(m, j), val);
    add(v * 2 + 1, m + 1, r, max(m + 1, i), j, val);
    t[v] = merge(t[v * 2], t[v * 2 + 1]);
}

pair<int, int> get(int v, int l, int r, int i, int j)
{
    push(v, l, r);
    if (i > j)
        return MP(mod, -mod);
    if (i == l && j == r)
        return t[v];

    int m = (l + r) / 2;
    return merge(
        get(v * 2, l, m, i, min(m, j)),
        get(v * 2 + 1, m + 1, r, max(m + 1, i), j)
    );
}


bool check(int len)
{

    build(1, 0, n);

    for (int i = 1; i <= n; i++)
        add(1, 0, n, i, n, 1);


    for (int x = 1; x <= n; x++)
    {
        for (int p = 0; p < pos[x].size(); p++)
        {
            int i = pos[x][p];
            add(1, 0, n, i, n, -1);
        }


        for (int p = 0; p < pos[x].size(); p++)
        {
            int i = pos[x][p];

            int m = p - len + 1;
            if (m < 0)
                continue;

            int j = pos[x][m];

            pair<int, int> dr = get(1, 0, n, i, n);
            pair<int, int> dl = get(1, 0, n, 0, j - 1);
            pair<int, int> d = MP(dr.first - dl.second, dr.second - dl.first);


            if ((d.second < 0 && len >= -d.second) || (d.first > 0 && len >= d.first) || (d.first <= 0 && d.second >= 0))
                return true;
        }

        for (int p = 0; p < pos[x].size(); p++)
        {
            int i = pos[x][p];
            add(1, 0, n, i, n, -1);
        }
    }

    return false;
}



int sequence(int nn, vector<int> aa)
{
    n = nn;
    for (int i = 1; i <= n; i++)
        a[i] = aa[i - 1];


    for (int i = 1; i <= n; i++)
        pos[a[i]].push_back(i);

    int l = 1, r = n;
    while (l <= r)
    {
        int m = (l + r) / 2;
        if (check(m))
        {
            ans = m;
            l = m + 1;
        }
        else
            r = m - 1;

    }

    return ans;
}

#ifdef death



void solve()
{
    int nn;
    vector<int> aa;
    cin >> nn;
    for (int i = 0; i < nn; i++)
    {
        int x;
        cin >> x;
        aa.push_back(x);
    }

    cout << sequence(nn, aa) << endl;
}

int main()
{
    fastIO;
    int T = 1;
    //cin >> T;
    while (T--)
        solve();
    return 0;
}
#endif // death

/*

9
1  1  2  3  4  3  2  1  1


14
2 6 2 5 3 4 2 1 4 3 5 6 3 2

*/

컴파일 시 표준 에러 (stderr) 메시지

sequence.cpp: In function 'bool check(int)':
sequence.cpp:113:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  113 |         for (int p = 0; p < pos[x].size(); p++)
      |                         ~~^~~~~~~~~~~~~~~
sequence.cpp:120:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  120 |         for (int p = 0; p < pos[x].size(); p++)
      |                         ~~^~~~~~~~~~~~~~~
sequence.cpp:139:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  139 |         for (int p = 0; p < pos[x].size(); p++)
      |                         ~~^~~~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 17 / 17
• Subtask 3: 0 / 7
• Subtask 4: 0 / 12
• Subtask 5: 0 / 13
• Subtask 6: 0 / 22
• Subtask 7: 0 / 18