Binary Indexed Tree (Fenwick Tree)
A Fenwick tree or binary indexed tree (BIT) is a data structure that can efficiently update elements and calculate prefix sums in a table of numbers 
Collection of bit mask operation
I have collected a few popular and useful bit operations 
Modular Inverse
In arithmetic, a modular multiplicative inverse of an integer a is an integer x such that the product a*x = 1 with respect to the modulus m 
Thinking in bets book summary
Thinking in Bets will teach you how to make smart decisions when you do not have all the facts. 
How to say mathematical expression in Japanese
I have prepared a summary on how to pronounce mathematical notation and formula in English and Japanese