Euclid's gcd algorithm, extended gcd algorithm and Chinese remainder theorem
Suggested Resources
https://crypto.stanford.edu/pbc/notes/numbertheory/euclid.html
https://discuss.codechef.com/questions/20842/a-tutorial-on-the-extended-euclids-algorithm
https://www.codechef.com/wiki/very-brief-tutorial-chinese-remainder-theorem
Suggested Problems
Fight for Attendence
Chef and cakes
Max Subarray GCD
Currency trouble
Marbles
Play with Floor and Ceil
Remainders Game
Buns
Cutting Figure
GCD Table
Little Elephant and Triangle
Nephren Runs a Cinema