Efficient Exponentiation in Java: The Fast Power Algorithm
Understanding Fast Exponentiation
Exponentiation is a mathematical operation that involves raising a base number to a specified power, expressed as be, where b is the base and e is the exponent.
The Fast Exponentiation Approach
The fast exponentiation algorithm (also known as exponentiation by squaring) is an optimized method for computing larg ...
Posted on Sat, 25 Jul 2026 16:49:53 +0000 by mnewhart
Expected Key Presses in the Klavir Problem
Notation
Let \(dp_i\) denote the expected number of attempts to correctly play the prefix \(1 \to i\), with \(dp_1 = n\).
The target melody is given by the array \(target_i\).
Analysis
When playing a melody, the current partially correct sequence falls into one of two cases:
The current suffix matches some prefix of the melody.
No suffix of ...
Posted on Mon, 13 Jul 2026 16:09:08 +0000 by rslnerd
Calculating Binomial Expansion Coefficients Modulo 10007
This article addresses the problem of finding the coefficient of the $x^n y^m$ term in the expansion of the polynomial $(ax + by)^k$. The solution involves applying the binoimal theorem and calculating combinations modulo 10007.
Binomial Theorem Application
The binomial theorem states that $(x+y)^k = \sum_{i=0}^{k} \binom{k}{i} x^{k-i} y^i$. In ...
Posted on Mon, 06 Jul 2026 16:23:12 +0000 by fangfang
Determine the Day of the Week After 20^22 Days (Lanqiao Cup 2022 Provincial Problem)
Problem Description
Given that today is Saturday, determine which day of the week it will be after 20^22 days. Note that days are represented as 1 (Monday) through 7 (Sunday).
Approach
This problem can be efficiently solved using modular arithmetic to avoid computing the extremely large value of 20^22 directly. Since the week cycles every 7 day ...
Posted on Sun, 31 May 2026 17:12:21 +0000 by dkphp2