Here are some common c programs and their algorithms:

If-else and switch statement :

  1. Program to find whether a number is even or odd.
  2. Program to find whether a number is prime or not.
  3. Program to find whether year is leap year or not. 
  4. Program to make a simple calculator using switch statement.

Looping / Iteration Statements (for, while, do-while) :

  1. Program to find whether a number is armstrong number or not.
  2. Program to swap two numbers using call by reference.
  3. Program to swap two numbers using call by value.
  4. Program to print a multiplication table for a given number.
  5. Program to print flyod’s triangle.
  6. Program to print pascal’s triangle
  7. Program to print the given series : 1+1/2+1/4+1/8+1/16………….
  8. Program to print the reverse of a number.
  9. Program to find the factorial of a number.
  10. Program to find the largest of n numbers.
  11. Program to find the smallest of n numbers.
  12. Program to check whether a number is palindrome or not.
  13. Program to print the fibonacci series.

Recursion :

  1. Program to print numbers without using loops.
  2. Program to reverse a number using recursion.
  3. Program to find the factorial of a number using recursion.
  4. Program to print fibonacci series using recursion
  5. Program to find HCF or GCD of a number using recusion.
  6. Program to find LCM of a number using recursion.
  7. Program to find the power using recusion.
  8. Program to solve the Tower of Hanoi Problem.

Strings in C :

  1. Program to find length of a string.
  2. Program to compare two strings.
  3. Program to concatenate two strings.
  4. Program to reverse a string.
  5. Program to reverse a string using strrev() function. 
  6. Program to find whether string is palindrome or not using function.
  7. Program to find whether a string is palindrome or not, without using function.
  8. Program to search a substring in a string.
  9. Program to find a substring from a string.
  10. Program to find the number of words in a string.
  11. Program to capitalise first letter of each word in a sentence.
  12. Program to count the number of vowels in a string.
  13. Program to replace each space with a hyphen.
  14. Program to reverse each word individually in a sentence.
  15. Program to find number of whitespaces and new lines in a string.

Array & Matrix:

  1. Program to delete dupicate elements from an array.
  2. Program to traverse and print a matrix.
  3. Program to perform addition of matrices.
  4. Program to perform substraction of matrices.
  5. Program to perform matrix multiplication.
  6. Program to find the transpose of a matrix.

Searching & Sorting :

  1. Program to perform Linear Search.
  2. Program to perform Binary Search.
  3. Program to perform Binary Search using recursion.
  4. Program to perform Bubble sort.
  5. Program to perform Selection sort.
  6. Program to perform Insertion sort.
  7. Program to perform Quick Sort.
  8. Program to perform Merge Sort.

Patterns  :

  1. PATTERN WITH ALPHABETS 1
  2. PATTERN WITH NUMBERS 1
  3. PATTERN 1
  4. PATTERN 2
  5. PATTERN 3

Miscellaneous :

  1. Program to generate random numbers.
  2. Program to find the roots of a quadratic equation.
  3. Program to illustrate use of Conditional operator.
  4. Program to convert Fahrenheit to Celsius.
  5. Program to swap two numbers without using third variable.

Numerical Techniques Implementations :

  1. BISECTION METHOD
  2. ITERATION METHOD
  3. REGULA FALSI METHOD
  4. NEWTON RAPHSON METHOD
  5. MULLER’S METHOD
  6. NEWTON FORWARD INTERPOLATION METHOD
  7. NEWTON BACKWARD INTERPOLATION METHOD
  8. GAUSS’S FORWARD INTERPOLATION METHOD
  9. GAUSS’S BACKWARD INTERPOLATION METHOD
  10. STIRLING’S METHOD
  11. BESSEL’S FORMULA OF INTERPOLATION
  12. LAGRANGE’S FORMULA OF INTERPOLATION
  13. SIMPSON’S 1/3 RULE
  14. SIMPSON’S 3/8 RULE
  15. TRAPEZOIDAL FORMULA

Operating System Lab Programs :

  1. FCFS CPU SCHEDULING
  2. SJF CPU SCHEDULING
  3. SRTF CPU SCHEDULING
  4. PRIORITY CPU SCHEDULING
  5. ROUND ROBIN CPU SCHEDULING
  6. LEXICAL ANALYSER FOR if statement
  7. LEXICAL ANALYSER FOR ARITHMETIC STATEMENTS
  8. LEXICAL ANALYSER using LEX
  9. NFA TO DFA CONVERSION
  10. OPERATOR PRECEDENCE PARSING
  11. SHIFT REDUCE PARSING
  12. RECURSIVE DECENT PARSING
  13. CODE OPTIMIZATION
  14. CODE GENERATION