Recursion
A method of solving a problem where the solution depends on solutions to smaller instances of the same problem.
Recursion is a programming technique where a function calls itself directly or indirectly. It involves a 'base case' to terminate the process and a 'recursive step' that breaks the problem into a simpler version of itself. It is particularly elegant for solving problems involving trees, fractals, and mathematical sequences.
graph LR
Center["Recursion"]:::main
Rel_algorithm["algorithm"]:::related -.-> Center
click Rel_algorithm "/terms/algorithm"
Rel_adiabatic_quantum_computation["adiabatic-quantum-computation"]:::related -.-> Center
click Rel_adiabatic_quantum_computation "/terms/adiabatic-quantum-computation"
Rel_search_algorithm["search-algorithm"]:::related -.-> Center
click Rel_search_algorithm "/terms/search-algorithm"
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🧠 Knowledge Check
🧒 Explain Like I'm 5
Recursion is like looking into two mirrors facing each other. You see a picture of yourself, holding a picture of yourself, holding a picture of yourself... In coding, it's a [function](/en/terms/function) that uses itself to get the final answer.
🤓 Expert Deep Dive
Tail Call Optimization (TCO) is crucial for preventing stack overflows in recursive functions by reusing the stack frame for the next call. Recursion often provides a more natural mapping to inductive mathematical proofs, but can be memory-intensive compared to iterative solutions due to stack frame overhead.