제출 #1013689

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1013689		Thunnus	Global Warming (CEOI18_glo)	C++17	100 / 100	40 ms	7956 KiB

glo

#include<bits/stdc++.h>
using namespace std;
using i64 = long long;
#define int i64
#define vi vector<int>
#define vvi vector<vi>
#define vb vector<bool>
#define pii pair<int, int>
#define fi first
#define se second
#define sz(x) (int)(x).size()

signed main(){
    ios_base::sync_with_stdio(false); cin.tie(0);
    int n, x, ans = 0;
    cin >> n >> x;
    vi a(n);
    for(int &i : a)
        cin >> i;

    // longest increasing subsequence ending at i
    vi lis, at_lis(n);
    for(int i = 0; i < n; i++){
        int pos = lower_bound(lis.begin(), lis.end(), a[i]) - lis.begin();
        if(pos == sz(lis))
            lis.emplace_back(a[i]);
        else
            lis[pos] = a[i];
        at_lis[i] = pos + 1;
    }

    // longest decreasing subsequence ending at i of reverse
	// = longest increasing subsequence starting at i
    lis = vi(n, INT32_MAX);
    for(int i = n - 1; i >= 0; i--){
        int pos = lower_bound(lis.begin(), lis.end(), -a[i] + x) - lis.begin();
        /*if(at_lis[i] + pos > ans)
			cout << "i: " << i << " val: " << at_lis[i] + pos << "\n";*/
        ans = max(ans, at_lis[i] + pos);
        int insert_pos = lower_bound(lis.begin(), lis.end(), -a[i]) - lis.begin();
        lis[insert_pos] = -a[i];
    }
    cout << ans;
    return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 13 / 13
• Subtask 4: 10 / 10
• Subtask 5: 20 / 20
• Subtask 6: 17 / 17
• Subtask 7: 25 / 25