K上升序列总和

Given an array of integers, find out number of ways in which you can select increasing subsequences of length k(k<=n).

for eg array is 1 4 6 2 5 & k=3
then the answer is :1 4 5, 1 2 5,1 4 6,
so ways are 3

int solve(int a[], int size, int K)
{
	int buf[size][K];
	memset(buf, 0, sizeof(buf));

	for (int i = 0; i < size; i++)
	{
		buf[i][1] = 1;
	}

	for (int i = 1; i < size; i++)
	{
		for (int j = 0; j < i; j++)
		{
			if (a[i] > a[j])
			{
				for (int m = 1; m < K; m++)
				{
					buf[i][m+1] += buf[j][m];
				}
			}
		}
	}

	int result = 0;
	for (int i = 0; i < size; i++)
	{
		result += buf[i][K];
	}

	return result;
}