rotate and find_min

find_min_of_rotated.py

def swap(a, b):
	temp = a
	a = b
	b = temp
	return (a,b)

def rotate(arr, by):
	if len(arr)%by == 0:
		for i in range(by):
			start, pos = arr[i], i+by
			for j in range(len(arr)/by):
				arr[pos%len(arr)], start = swap(arr[pos%len(arr)], start) 
				pos += by	
	else:
		start, pos = arr[0], by
		for i in range(len(arr)):
			arr[pos%len(arr)], start = swap(arr[pos%len(arr)], start) 
			pos += by
	return arr

def find_min(arr, start, end):
	if(start >= end):
		return arr[start]
	mid = (start+end)/2
	if arr[mid] <= arr[end]:
		if arr[mid-1] > arr[mid]:
			return arr[mid]
		return find_min(arr, start, mid-1)
	else:
		return find_min(arr, mid+1, end)

#errors found were: take care of base recursion
#errors found were: add "return" recursion_method
#errors found were: no. of iterations were one less,
#errors found were: using % instead of /
print rotate([1,2,3,4],1) #output: [4,1,2,3]
print find_min(rotate([1,2,3,4],1),0,3) #output: 1
print rotate([1,2,3,4],3) #output: [2,3,4,1]
print find_min(rotate([1,2,3,4],3),0,3) #output: 1
print rotate([1,2,3,4],2) #output: [3,4,1,2]
print find_min(rotate([1,2,3,4],2),0,3) #output: 1
print find_min([1,2],0,1)
print find_min([1,1],0,1)
print find_min([1],0,0)