Easy way to remember Strassen's Matrix Equation in C++

It is a matrix multiplication algorithm is based on divide and conquer method. It is used to multiply two matrices of the same size,

Finding multiplication of two matrices−

The strassen’s Algorithm reduces overhead for multiplication by simplifying the multiplication.

Here is the multiplication made using the strassen’s Algorithm: 

M1 = a*(f - h)
 M2 = (a + b)*h
 M3 = (c + d)*e
 M4 = d*(g - e)
 M5 = (a + d)*(e + h)
 M6 = (b - d)*(g + h)
 M7 = (a - c)*(e + f)

This can be easily remembered and the algorithm code can be decoded. For this we have a few rules, first remember these 6 things−

• Use AHED for the first 4 values of M.
• Use Diagonal multiplication for the 5th value of M.
• Use last CR (last col from mat 1 and last row form mat 2) for 6th value of M.
• Use first CR(first col from mat 1 and first row form mat 2) for 7th value of M.
• While considering elements of row add them and in case of columns subtract them.
• The update values after that using adjacent values.

Using these ways we can easily remember the values.

Sudhir sharma

Published on 22-Jan-2021 12:29:59

• Related Questions & Answers
• What's an easy way to read a random line from a file in the Unix command line?
• Easy way to re-order columns in MySQL?
• What's the best way to trim std::string in C++?
• What's the best way to detect a 'touch screen' device using JavaScript?
• What's the simplest way to print a Java array?
• What's the best way to do this? VBA, etc
• What's the best way to ensure a happy marriage?
• Snagit Tool: Taking Better Screenshots the Easy Way
• How to use pip to install python modules in easy way?
• What's the canonical way to check for type in python?
• How will you explain Python namespaces in easy way?
• What is the easy way to make friends in a new school?
• The simplest way to get the user's current location on Android
• What's the best way to open new browser window using JavaScript?
• Pascal's Triangle in C++