# Formula to compute number of groups from given points with overlap

The problem is kind of easy to understand.

Given is some points, say 10 points. (I am using numbering for understanding)

0 1 2 3 4 5 6 7 8 9

Now group these such that the group size is 5 and there is no overlap
so, there can be 2 groups. the groups are (0 1 2 3 4) & (5 6 7 8 9)

Now group the above given points such that the group size is 5 and overlap is 1
so, there can be 3 groups. the groups are (0 1 2 3 4) & (4 5 6 7 8) & (8 9) //Note: don't worry that (8 9) group has only 2 points

Now group the above given points such that the group size is 5 and overlap is 3
so, there can be 3 groups. the groups are (0 1 2 3 4) & (3 4 5 6 7 ) & (6 7 8 9)

Similarly.....

group size | overlap size | number of groups
5 | 0 | 2
5 | 1 | 3
5 | 2 | 3
5 | 3 | 4
5 | 4 | 6

I am looking for some generalized formula to compute the number of groups

So, given the group size and overlap size, find the number of groups. Can anyone help me with finding a generalized formula