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Computer Science Introduction to Algorithms Algorithms in Code Recursive Binary Search

Martin Owaga Mboya
Martin Owaga Mboya
13,595 Points
Posted by Martin Owaga Mboya
Martin Owaga Mboya
13,595 Points

Recursive Binary Search

Why does he not subtract one from the length of the list like he did in the previous video?

1 Answer

Mark Sebeck
MOD
Mark Sebeck
Treehouse Moderator 38,297 Points
Mark Sebeck
Mark Sebeck
Treehouse Moderator 38,297 Points

Hi Martin. Great question. In the binary search video he wanted to find the position of the last element in the list. Because lists start at 0 the position is going to be the number of elements - 1. (if there are 10 elements they will be 0 to 9). In this video he just wants to check if the list is empty. He's not looking for the last element. He knows if the length equals 0 then the list is empty. Hope this helps Martin.