This C program finds GCD and LCM using recursion with the Euclidean algorithm. The GCD (Greatest Common Divisor) is the largest number that divides both inputs with no remainder. The LCM (Least Common Multiple) is the smallest number divisible by both. Once the GCD is known, the LCM follows from a simple identity: GCD(a, b) …
The Fibonacci series in C is a sequence where each number is the sum of the two preceding ones, starting from 0 and 1: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, … This page covers three approaches — iterative series printing, a recursive function, and a side-by-side comparison of their time and …
The factorial program in C is one of the most common exercises for learning recursion and loops. The factorial of a non-negative integer n, written n!, is the product of all positive integers from 1 to n. By definition, 0! = 1. This page covers two approaches — iterative and recursive — with compile-verified code, …
Shell sort is a generalization of insertion sort that sorts elements far apart before sorting adjacent ones. Invented by Donald Shell in 1959, it repeatedly applies insertion sort on sublists of decreasing “gap” sizes until the gap reaches 1 — at which point one final insertion sort on the nearly-sorted array runs in near-linear time. …
Merge sort in C is a classic divide-and-conquer sorting algorithm that guarantees O(n log n) time in all cases. It splits an array into halves, recursively sorts each half, then merges the sorted halves back together. Unlike bubble sort or insertion sort, merge sort never degrades to O(n²) — making it the preferred choice when …
Insertion sort is one of the simplest sorting algorithms and works exactly the way you sort a hand of playing cards. You take one card at a time and insert it into its correct position among the cards already sorted in your hand. It sorts the array one element at a time, building the sorted …