Problems
Doya and XOR#11855
Medium · Bitwise Operations · Divide and Conquer · Combinatorics · Sorting
Quad#11854
Easy · Constructive Algorithms · Brute force
Unique ID#11853
Easy · Hashing
De3b0o's MathModel Ideal Gift#11857
Very hard · Number theory · Prime factorization · Binary Search · Prefix Sums
Obsessed with Hatsune Miku#11856
Very hard · Sorting · Binary Search · Prefix Sums · Greedy algorithms