BdOI Preliminary

Topics for the preliminary round of the Bangladesh Olympiad in Informatics (targeting ~1100 Codeforces rating).

Search and Recursion

Bruteforce

An introduction to bruteforce algorithms.

Complete Search

Exploring the complete search (brute-force) approach to problem-solving.

Introduction to Recursion

Understanding the concept of recursion.

Recursive Backtracking

Solving problems with recursive backtracking.

Sorting and Binary Search

Bubble and Selection Sort

Understanding simple sorting algorithms.

Merge and Quick Sort

Efficient sorting algorithms.

Custom Comparators

Sorting with custom comparison functions.

Binary Search on Array

Applying binary search on sorted arrays.

Binary Search the Answer

Using binary search to find the answer to a problem.

Greedy and Pointers

Greedy Algorithms

An introduction to greedy algorithms.

Two Pointers

An introduction to the two-pointer technique.

Math and Bitwise Operations

Prefix Sums

Learn how to use prefix sums to efficiently calculate subarray sums.

Bitwise Operators

Understanding and using bitwise operators in competitive programming.

Modular Arithmetic

Basic operations in modular arithmetic.

Basic Modular Arithmetic

Learn the basics of modular arithmetic, including addition, subtraction, and multiplication.

Primes and Divisors

Generating prime numbers and finding divisors.

Basic Number Theory

An introduction to basic number theory concepts like GCD, LCM, and prime factorization.