Submission #954435

#	Time	Username	Problem	Language	Result	Execution time	Memory
954435		Mher777	Sequence (APIO23_sequence)	C++17	0 / 100	54 ms	20048 KiB

sequence

#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <iomanip>
#include <array>
#include <string>
#include <algorithm>
#include <cmath>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
#include <vector>
#include <stack>
#include <queue>
#include <deque>
#include <bitset>
#include <list>
#include <iterator>
#include <numeric>
#include <complex>
#include <utility>
#include <random>
#include <cassert>
#include <fstream>
#include "sequence.h"
using namespace std;
mt19937 rnd(7069);
typedef int itn;
typedef long long ll;
typedef unsigned long long ull;
typedef double db;
typedef float fl;
typedef long double ld;
using vi = vector<int>;
using vll = vector<ll>;
using mii = map<int, int>;
using mll = map<ll, ll>;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
#define ff first
#define ss second
#define pub push_back
#define pob pop_back
#define puf push_front
#define pof pop_front
#define mpr make_pair
#define yes cout<<"Yes\n"
#define no cout<<"No\n"
#define all(x) (x).begin(), (x).end()
const int MAX = int(2e9 + 5);
const ll MAXL = ll(1e18) + 5ll;

const int N = 500005;
int a[N];
int n;

int sol() {
    vi cnt1(n + 1), cnt2(n + 1), pref1(n + 1), pref2(n + 1), v1, v2;
    int ret = 0;
    bool f = true;
    for (int i = 1; i < n; ++i) {
        if (a[i] <= a[i + 1] && f) {
            v1.pub(a[i]);
        }
        else {
            f = false;
            v2.pub(a[i]);
        }
    }
    if (a[n] >= a[n - 1] && f) {
        v1.pub(a[n]);
    }
    else {
        v2.pub(a[n]);
    }
    for (int i = v1.size() - 1; i >= 0; --i) {
        ++cnt1[v1[i]];
        if (i == v1.size() - 1) pref1[v1[i]] = 1;
        else pref1[v1[i]] = pref1[v1[i + 1]] + 1;
    }
    for (int i = 0; i < v2.size(); ++i) {
        ++cnt2[v2[i]];
        if (i == 0) pref2[v2[i]] = 1;
        else pref2[v2[i]] = pref2[v2[i - 1]] + 1;
    }
    for (int i = 1; i <= n; ++i) {
        ret = max({ ret,cnt1[i],cnt2[i] });
        int len = pref1[i] + pref2[i], pref = cnt1[i] + cnt2[i];
        if (pref >= len / 2 + len % 2) ret = max(ret, cnt1[i] + cnt2[i]);
    }
    return ret;
}

int sequence(int N, std::vector<int> A) {
    n = N;
    for (int i = 1; i <= n; ++i) {
        a[i] = A[i - 1];
    }
    return sol();
}

/*
7
1 2 3 1 2 1 3
3

9
1 1 2 3 4 3 2 1 1
2

14
2 6 2 5 3 4 2 1 4 3 5 6 3 2
3
*/

Compilation message (stderr)

sequence.cpp: In function 'int sol()':
sequence.cpp:78:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   78 |         if (i == v1.size() - 1) pref1[v1[i]] = 1;
      |             ~~^~~~~~~~~~~~~~~~
sequence.cpp:81:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   81 |     for (int i = 0; i < v2.size(); ++i) {
      |                     ~~^~~~~~~~~~~

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