This program reads a filename and a count n from the command line, reads the first n characters from the file, reverses them in-place using a two-pointer swap, and prints the result. It demonstrates combining command-line argument parsing, file I/O with fread(), and in-place string reversal in a single practical program. The original post used …
Copying a file in C demonstrates how to combine file I/O functions (fopen, fgetc, fputc, fclose) with command-line arguments to build a practical utility. The program reads filenames from argv, opens both files, copies byte-by-byte, and reports how many bytes were transferred. The original version used conio.h, process.h, void main(), and stored the return value …
This C program to generate random numbers uses the standard library functions rand() and srand(). rand() returns a pseudo-random integer between 0 and RAND_MAX (at least 32767). “Pseudo-random” means the sequence is determined by a starting value called the seed. Seeding with time(NULL) ensures a different sequence every time the program runs. Key Functions Function …
Complex number operations in C using structures demonstrate how to pair two related values — a real part and an imaginary part — into a single user-defined type. Complex numbers are written as a + bi, where a is the real component and b is the imaginary component (i = √−1). They appear in signal …
Roman numerals to decimal conversion is a classic algorithm problem that tests your ability to identify the subtractive notation rule. Roman numerals use seven symbols (I, V, X, L, C, D, M) and a key rule: when a smaller value symbol appears before a larger one, it is subtracted instead of added. So IV = …
The 2’s complement of a binary number in C is the way modern computers represent negative integers. In an 8-bit system, +5 is stored as 00000101 and −5 is stored as 11111011 (the 2’s complement of 00000101). Using 2’s complement, subtraction becomes ordinary addition and there is only one representation of zero — which is …