Lecture 4: Fundamental Number Theory and Mathematical Concepts for Competitive Programming
An in-depth lecture on essential number theory and math concepts crucial for competitive programming. Use code 'DSA20' for an extra 20% discount on all Decode batches. Enroll now at https://pwskills.com/category/programming-courses/.

College Wallah
21.6K views • Jan 14, 2025

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Use "DSA20" To Get Extra 20% Off On All Decode Batches
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Lecture 4 delves into the fundamentals of number theory and key mathematical concepts essential for competitive programming. It covers topics like prime numbers, divisibility rules, modular arithmetic, and gcd (greatest common divisor), providing a strong foundation for solving algorithmic problems efficiently. This lecture equips learners with the mathematical tools to approach challenges with confidence.
Video Timestamps:-
00:00:00 Introduction
00:02:20 What is Number Theory?
00:03:00 Today’s Agenda
00:04:55 Prime Numbers
00:18:00 Finding factors of a Number
00:29:05 Checking Prime Number in Efficient Time
00:31:45 Sieve of Eratosthenes
00:53:00 Time Complexity of Sieve of Eratosthenes
00:56:00 Why Sieve is Better?
01:01:20 Problem A - Primes
01:10:20 Problem B - Prefix Sum Primes
01:23:25 Problem C - Factorise N+M
01:30:30 Problem D - Prime Deletion
01:38:30 Problem E - Prime Substraction
01:45:35 Modular Arithmetic
01:54:54 Binary Exponentiation
02:11:55 Modular Exponentiation
02:20:35 Problem F - Modular Exponentiation
02:36:35 GCD - Greatest Common Divisor
02:43:00 Euclidean Algorithm
02:56:00 LCM - Lowest Common Multiple
03:01:50 Problem G - LCM Problem
03:11:05 Problem H - GCD vs LCM
03:17:30 Problem I - Madoka and Strange Thoughts
03:26:45 Finding Factorial of a Number
03:30:20 Finding value of nCr
03:40:40 Problem J - Password
03:48:50 Problem K - Required Remainder
03:58:20 Conclusion
Resources:
Sieve of Eratosthenes: https://cp-algorithms.com/algebra/sieve-of-eratosthenes.html
Euclidean algorithm: https://cp-algorithms.com/algebra/euclid-algorithm.html
Time Complexity of Euclid’s Algorithm: https://www.baeldung.com/cs/euclid-time-complexity
nCr: https://cp-algorithms.com/combinatorics/binomial-coefficients.html
Binary Exponentiation: https://cp-algorithms.com/algebra/binary-exp.html
Problems Solved:
B. Primes: https://codeforces.com/problemset/gymProblem/102267/B
A. Prefix Sum Primes: https://codeforces.com/problemset/problem/1149/A
A. Factorise N+M: https://codeforces.com/problemset/problem/1740/A
A. Prime Deletion: https://codeforces.com/problemset/problem/1861/A
A. Prime Subtraction: https://codeforces.com/problemset/problem/1238/A
A. Modular Exponentiation: https://codeforces.com/problemset/problem/913/A
A. LCM Problem: https://codeforces.com/problemset/problem/1389/A
A. Required Remainder: https://codeforces.com/problemset/problem/1374/A
A. GCD vs LCM: https://codeforces.com/problemset/problem/1665/A
A. Password: https://codeforces.com/problemset/problem/1743/A
A. Madoka and Strange Thoughts: https://codeforces.com/problemset/problem/1717/A
Lecture 4 : Understanding Number Theory and Maths Concepts | Competitive Programming
#NumberTheory #CompetitiveProgramming #Mathematics #GCD #ModularArithmetic #PrimeNumbers #Algorithms
Want to Get Enrolled in Decode Batches? Enroll Now-https://pwskills.com/category/programming-courses/?utm_source=organic&utm_medium=social_media&utm_campaign=winter_sale
Lecture 4 delves into the fundamentals of number theory and key mathematical concepts essential for competitive programming. It covers topics like prime numbers, divisibility rules, modular arithmetic, and gcd (greatest common divisor), providing a strong foundation for solving algorithmic problems efficiently. This lecture equips learners with the mathematical tools to approach challenges with confidence.
Video Timestamps:-
00:00:00 Introduction
00:02:20 What is Number Theory?
00:03:00 Today’s Agenda
00:04:55 Prime Numbers
00:18:00 Finding factors of a Number
00:29:05 Checking Prime Number in Efficient Time
00:31:45 Sieve of Eratosthenes
00:53:00 Time Complexity of Sieve of Eratosthenes
00:56:00 Why Sieve is Better?
01:01:20 Problem A - Primes
01:10:20 Problem B - Prefix Sum Primes
01:23:25 Problem C - Factorise N+M
01:30:30 Problem D - Prime Deletion
01:38:30 Problem E - Prime Substraction
01:45:35 Modular Arithmetic
01:54:54 Binary Exponentiation
02:11:55 Modular Exponentiation
02:20:35 Problem F - Modular Exponentiation
02:36:35 GCD - Greatest Common Divisor
02:43:00 Euclidean Algorithm
02:56:00 LCM - Lowest Common Multiple
03:01:50 Problem G - LCM Problem
03:11:05 Problem H - GCD vs LCM
03:17:30 Problem I - Madoka and Strange Thoughts
03:26:45 Finding Factorial of a Number
03:30:20 Finding value of nCr
03:40:40 Problem J - Password
03:48:50 Problem K - Required Remainder
03:58:20 Conclusion
Resources:
Sieve of Eratosthenes: https://cp-algorithms.com/algebra/sieve-of-eratosthenes.html
Euclidean algorithm: https://cp-algorithms.com/algebra/euclid-algorithm.html
Time Complexity of Euclid’s Algorithm: https://www.baeldung.com/cs/euclid-time-complexity
nCr: https://cp-algorithms.com/combinatorics/binomial-coefficients.html
Binary Exponentiation: https://cp-algorithms.com/algebra/binary-exp.html
Problems Solved:
B. Primes: https://codeforces.com/problemset/gymProblem/102267/B
A. Prefix Sum Primes: https://codeforces.com/problemset/problem/1149/A
A. Factorise N+M: https://codeforces.com/problemset/problem/1740/A
A. Prime Deletion: https://codeforces.com/problemset/problem/1861/A
A. Prime Subtraction: https://codeforces.com/problemset/problem/1238/A
A. Modular Exponentiation: https://codeforces.com/problemset/problem/913/A
A. LCM Problem: https://codeforces.com/problemset/problem/1389/A
A. Required Remainder: https://codeforces.com/problemset/problem/1374/A
A. GCD vs LCM: https://codeforces.com/problemset/problem/1665/A
A. Password: https://codeforces.com/problemset/problem/1743/A
A. Madoka and Strange Thoughts: https://codeforces.com/problemset/problem/1717/A
Lecture 4 : Understanding Number Theory and Maths Concepts | Competitive Programming
#NumberTheory #CompetitiveProgramming #Mathematics #GCD #ModularArithmetic #PrimeNumbers #Algorithms
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Duration
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Published
Jan 14, 2025
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