dsa2 min read
Make Sum Divisible by P — Prefix Mod + HashMap
Find the smallest subarray to remove so the remaining sum is divisible by p using prefix modular arithmetic.
Read →
Modular
4 articles
dsa1 min read
Subarray Sum Divisible by K — Prefix Mod HashMap
Count subarrays with sum divisible by k using prefix mod frequencies and the complement map pattern.
Read →
dsa3 min read
Chinese Remainder Theorem: Solving Modular Equations
Solve systems of modular congruences with the Chinese Remainder Theorem. Fundamental for cryptography and competitive math.
Read →
dsa4 min read
Modular Arithmetic: Fast Exponentiation and Inverse
Master modular arithmetic for competitive programming: binary exponentiation O(log n), modular inverse, and Chinese Remainder Theorem.
Read →