Ep3-GCD-And-Totient.md

Part 2 Episode 3/4: GCD and Totient Function

Solid Introductory Read

Euclidean GCD Algorithm

Tutorial: Euclidean Algorithm for GCD

A very useful inbuilt function in C++ is the std::gcd function in C++ to calculate the GCD of two numbers.

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Euler Totient Function

Being defined for an integer n as the number of integer less than or equal to n and co-prime with n, the totient function is an important one to read about.

Tutorial: The Phi Function

Notes from HackerEarth

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Here are some links to practice question based on the aforementioned topics:

1. Codeforces 664 A

2. Codechef FLOW16

3. SPOJ CEQU

Challenge Problems:

1. Codeforces 1350 C

2. Codeforces 1295 D