Submission #20,707

20707

2026-01-08 18:06:01

cpp17

Accepted 50/50

18ms

512 KiB

#include <iostream>
#include <vector>

using namespace std;


int main()
{
	int n, k, count = 0;
	cin >> n >> k;
	for (int i = 0; i < n; i++)
	{
		int x;
		cin >> x;
		if (x == 1)
		{
			count++;
		}
	}

	long long ans = 0;

	for (int i = 0; i < count; i++)
	{
		if (count - i + 1 < k)
		{
			break;
		}
		ans += max(0, count - i - k + 1);
	}
	cout << ans;
}

	Sum	Test	Verdict		Time	Memory
base	50/50
		1	Accepted	0/0	1ms	500 KiB
		2	Accepted	0/0	1ms	500 KiB
		3	Accepted	0/0	18ms	316 KiB
		4	Accepted	2/2	1ms	316 KiB
		5	Accepted	2/2	1ms	376 KiB
		6	Accepted	2/2	1ms	316 KiB
		7	Accepted	3/3	1ms	316 KiB
		8	Accepted	3/3	1ms	316 KiB
		9	Accepted	3/3	2ms	500 KiB
		10	Accepted	2/2	2ms	316 KiB
		11	Accepted	3/3	1ms	316 KiB
		12	Accepted	2/2	1ms	316 KiB
		13	Accepted	3/3	1ms	316 KiB
		14	Accepted	2/2	17ms	400 KiB
		15	Accepted	2/2	17ms	396 KiB
		16	Accepted	3/3	18ms	396 KiB
		17	Accepted	3/3	17ms	316 KiB
		18	Accepted	3/3	18ms	396 KiB
		19	Accepted	3/3	17ms	396 KiB
		20	Accepted	3/3	17ms	404 KiB
		21	Accepted	3/3	18ms	396 KiB
		22	Accepted	3/3	18ms	512 KiB