2019-02-12 GA Algo

Divide and conquer

Merge sort

Binary search

Stock price

1. VP1 on A[1..n/2]
2. VP2 on A[n/2+1..n]
3. find smallest in A[1..n/2], bigest in A[n/2+1..n]
   

Exponential

Given a, n, output a**n
Naive: T(n)=T(n-1)+1=n
Smart: T(n)=T(n/2)+1=logn

Fibonacci

Naive: O(n)
Geeky: equation
Theorem:

Lightbulb technique

Karatsuba multiplication

Toy: addition of n-bit numbers, A=a_1,..a_n, B=b_1..b_n
C=AB, O(n^2)

Strassen multiplication

nxn matrix