An integer is even if it is divisible by 2 with no remainder, and odd if dividing by 2 leaves a remainder of 1. Zero is even. Negative integers follow the same rule: −4 is even, −7 is odd. This program uses the modulo operator % to determine parity in a single if-else check. Number …
Simple interest is the straightforward way to calculate interest on a principal amount over time. The formula is SI = (P × R × T) / 100, where P is the principal, R is the annual interest rate as a percentage, and T is the time in years. This program asks for all three values …
The area of a circle is A = π r² and the circumference is C = 2πr, where r is the radius. This program computes both from a user-supplied radius. Key points: use radius * radius instead of pow(radius, 2) (no need for the math library for a simple square), define π as a high-precision …
Swapping two variables is one of the most common operations in sorting, data structure manipulation, and algorithm implementation. There are three standard methods: using a temporary variable (clearest), arithmetic (no temp, but overflow risk), and XOR bit manipulation (no temp, no overflow, but tricky for same-variable self-swap). All three produce the same result — understanding …
Finding all integers in a range that are divisible by a given number is a classic loop exercise. The key tool is the modulo operator % — if i % 7 == 0, then i is exactly divisible by 7 with no remainder. This post shows two programs: one for the classic 100–200 range, and …
Given a list of integers, separate them into two groups — even numbers (divisible by 2) and odd numbers (not divisible by 2) — and report the sum and count of each group. This is a classic array-scanning problem that demonstrates the modulo operator, accumulator variables, and loop-based input. The original post had no code; …