Does the Question say that the sub sequence **s[1],s[2], …,s[k]** be the continuous elements of array a, but not randomly picked elements in an ascending order.

**For example**

Let **A= { 1,2,3,4,5,6,7,8}**

then

Sub sequence possible can be **S={ 2,3,4,5}**

But **S={ 2,4,7 }** is NOT possible.

just confused about sub sequence, cleared about the AP.

Thanks