Freaks City

Tile Pattern Problem: We have a 10^9×10^9 grid where each cell's color is determined by (i%n, j%n). We're given an n×n character matrix and need to answer q queries about the number of black cells in specified rectangular regions. Solution: We use a 2D prefix sum approach to efficiently count black cells in any rectangle. #include <iostream ...

Problem 1: Optimized Dynamic Programming with Prefix Sums This problem involves a basic dynamic programming approach where we process from the end to the beginning. The naive solution has a time complexity of O(n²), but we can optimize it using prefix sums and binary search. We maintain a prefix sum array and for each position, use binary searc ...