Problem Statement Write a C program to find the day of the week from a date of birth. For example, given 02/04/2017 (2nd April 2017), the program should tell you it was a Sunday. The Approach Pick a base year whose January 1st is a known weekday. We use 1900 (Jan 1, 1900 was a …
Chapter 5: Pointers and Arrays is the chapter C beginners fear most — and with reason. K&R covers pointer arithmetic, the equivalence between pointers and arrays, pointers to functions, and multi-dimensional arrays. The exercises build real utilities: getfloat, strncpy/strncat/strncmp from scratch, a tail command, a sort program with -r/-n/-f/-d flags, and a full C declaration …
First Come First Served (FCFS) is the simplest CPU scheduling algorithm used by an operating system — processes are executed strictly in the order they arrive, with no interruption once a process starts running. It works exactly like a queue at a ticket counter: whoever arrives first gets served first, and everyone else waits their …
Chapter 4: Functions and Program Structure is where K&R builds a non-trivial program: a reverse Polish notation (RPN) calculator. The exercises extend it — adding modulo, unary minus, variables, and last-printed-value recall. Other exercises cover recursive printd, recursive itoa, and the C preprocessor. Exercise 4-12 (recursive itoa) and 4-13 (recursive reverse) are elegance tests. These …
This classic exercise asks you to encrypt and decrypt a password in C. The right teaching tool for it is the XOR cipher: XOR each character with a key byte, and XOR-ing a second time with the same key restores the original — one function does both directions. This page gives you a tested implementation …
C Program to Solve the Producer-Consumer Problem Using Semaphores The producer-consumer problem (also called the bounded-buffer problem) is a classic process synchronization problem. A producer process generates data items while a consumer process reads them; a semaphore enforces the ordering so the consumer never reads ahead of the producer. Note: This program uses POSIX System …