Submission #385802

#	Time	Username	Problem	Language	Result	Execution time	Memory
385802		SansPapyrus683	Global Warming (CEOI18_glo)	C++17	100 / 100	128 ms	3564 KiB

glo

#include <bits/stdc++.h>

using namespace std;

int v[200005]; 
int dp[200005];

int main() {
    int n;
    int x;
	cin >> n >> x;
	for (int i = 0; i < n; i++) {
        cin >> v[i];
    }
	
    vector<int> lis(n, INT_MAX);
	int longest = 0;
	// longest increasing subsequence ending at i
	for (int i = 0; i < n; i++) {
		int j = lower_bound(lis.begin(), lis.end(), v[i]) - lis.begin();
		lis[j] = v[i];
		dp[i] = j + 1;
		longest = max(longest, dp[i]);
	}
	
    lis = vector<int>(n, INT_MAX);
	// longest decreasing subsequence ending at i of reverse
	// = longest increasing subsequence starting at i
	for (int i = n - 1; i >= 0; i--) {
		int j = lower_bound(lis.begin(), lis.end(), -v[i] + x)-lis.begin();
		longest = max(longest, dp[i]+j);

        int jj = lower_bound(lis.begin(), lis.end(), -v[i]) - lis.begin();
		lis[jj] = -v[i];
	}
	cout << longest << endl;
}

• 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