Submission #541318

#	Time	Username	Problem	Language	Result	Execution time	Memory
541318		Jomnoi	Financial Report (JOI21_financial)	C++17	17 / 100	46 ms	3584 KiB

Main

#include <bits/stdc++.h>
#define DEBUG 0
using namespace std;

const int N = 3e5 + 10;
const int M = 7e3 + 10;
const int INF = 1e9 + 7;

int a[N];
int dp[M][M], mx[2][M];

int main() {
    cin.tie(0)->sync_with_stdio(0);
    int n, d;
    cin >> n >> d;
    for(int i = 1; i <= n; i++) {
        cin >> a[i];
    }

    int ans = 0;
    if(d == 1) {
        int ma = 0;
        stack <int> stk;
        for(int i = n; i >= 1; i--) {
            while(!stk.empty() and stk.top() <= a[i]) {
                stk.pop();
            }

            stk.push(a[i]);
            ma = max(ma, (int)stk.size());
        }
        ans = ma;
    }
    else if(d == n) {
        vector <int> lis;
        for(int i = 1; i <= n; i++) {
            auto it = lower_bound(lis.begin(), lis.end(), a[i]);
            if(it == lis.end()) {
                lis.push_back(a[i]);
            }
            else {
                *it = a[i];
            }
        }
        ans = lis.size();
    }
    else if(n <= 7000) {
        vector <int> vec;
        vec.push_back(-INF);
        for(int i = 1; i <= n; i++) {
            vec.push_back(a[i]);
        }

        sort(vec.begin(), vec.end());
        vec.resize(unique(vec.begin(), vec.end()) - vec.begin());
        for(int i = 1; i <= n; i++) {
            a[i] = lower_bound(vec.begin(), vec.end(), a[i]) - vec.begin();
        }

        for(int j = 1; j < vec.size(); j++) {
            int now = j % 2;
            int prv = now ^ 1;
            deque <pair <int, int>> dq1, dq2;
            for(int i = 1; i <= n; i++) {
                while(!dq1.empty() and dq1.front().second < i - d) {
                    dq1.pop_front();
                }
                while(!dq2.empty() and dq2.front().second < i - d) {
                    dq2.pop_front();
                }

                if(j == a[i]) {
                    int ma = 0;
                    if(!dq1.empty()) {
                        ma = max(ma, dq1.front().first);
                    }
                    dp[i][j] = ma + 1;
                }
                if(j >= a[i] and !dq2.empty()) {
                    dp[i][j] = max(dp[i][j], dq2.front().first);
                }

                while(!dq1.empty() and dq1.back().first <= mx[prv][i]) {
                    dq1.pop_back();
                }
                while(!dq2.empty() and dq2.back().first <= dp[i][j]) {
                    dq2.pop_back();
                }
                dq1.emplace_back(mx[prv][i], i);
                dq2.emplace_back(dp[i][j], i);
            }
            for(int i = 1; i <= n; i++) {
                mx[now][i] = max(mx[now][i], dp[i][j]);
            }
            ans = max(ans, mx[now][n]);
        }
    }
    else {
        assert(false);
    }
    cout << ans;
    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:60:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   60 |         for(int j = 1; j < vec.size(); j++) {
      |                        ~~^~~~~~~~~~~~

• Subtask 1: 0 / 14
• Subtask 2: 0 / 14
• Subtask 3: 0 / 20
• Subtask 4: 12 / 12
• Subtask 5: 5 / 5
• Subtask 6: 0 / 35