C Program to Print Prime Numbers in a Given Range – Trial Division and Sieve

This C program generates and prints all prime numbers in a given range and reports the total count. It uses an efficient is_prime() function with a √n bound, plus a Sieve of Eratosthenes for cases where you need all primes up to a large limit. Trial Division — Check Each Number in the Range For …

Infix to Prefix Conversion in C – Stack Algorithm with Code

Infix to prefix conversion in C turns an everyday expression like (A+B)*C into its prefix (Polish notation) form *+ABC, where every operator comes before its operands. Compilers and expression evaluators use prefix and postfix forms because they need no parentheses and no precedence rules to evaluate — the structure is unambiguous. The standard algorithm is …

C Program to demonstrate isalpha, isdigit, is space.

C Program to demonstrate the following functions:isalpha, isdigit, isspace.The same principles apply to isalnum, iscntrl, isgraph,islower, isprint, ispunct, isupper, isxdigit.In the standard library ctype.h all the above functions are declared.All the subroutines mentioned here, returns non zero(true), If the checked argument is true for the respective subroutines. Read more about C Programming Language . /************************************************************ …

K&R C Programs Exercise 7-7

Exercise 7-7. Modify the pattern finding program of Chapter 5 to take its input from a set of named files or, if no files are named, from the standard input. Should the file name be printed when a match is found? Yes — when searching multiple files the filename should prefix each matching line (the …

K&R C Programs Exercise 7-5

Exercise 7-5. Rewrite the postfix calculator of Chapter 4 to use scanf and/or sscanf to do the input and number conversion. The original Chapter 4 calculator used a custom getop() that read characters one at a time with getch/ungetch to recognise numbers vs operators. With scanf we replace that with a simpler approach: read one …

K&R C Programs Exercise 7-4

Exercise 7-4. Write a private version of scanf analogous to the private printf described in this section. Like minprintf, minscanf parses a format string and uses va_list to accept a variable number of pointer arguments. It reads from stdin and dispatches to the appropriate conversion — using scanf itself with a constructed sub-format string, so …