Data Structures and Algorithms · Foundations

Recursion

A function solving a problem by calling itself on a smaller version of the same problem.

Also known as: recursive functions, base case, call stack.

Start a lesson on Recursion

Learn first

• Complexity analysis: Describing how an algorithm's running time or memory grows as input size grows, using Big-O.

Leads to

• Divide-and-conquer sorting: Divide-and-conquer sorts, merge sort and quicksort, that beat O(n squared) by splitting the problem.
• Binary trees: A hierarchical structure where each node has at most two children.
• Backtracking: Trying a choice, recursing, and undoing it if it leads nowhere, to explore all possibilities.

Related topics

• Divide and conquer: Splitting a problem into independent smaller copies of itself, solving each, then combining.
• Backtracking: Trying a choice, recursing, and undoing it if it leads nowhere, to explore all possibilities.