【Stanford Online】Engineering: Algorithms1 NO.3 Divide & conquer algorithms

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

one crossing point  means one inversion!

 

Num of inversion measures the degree of differences between two sequences of the same set of numbers, => useful in recommendation system => search "collaborative filtering"

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 https://en.wikipedia.org/wiki/Matrix_multiplication_algorithm