For exercising reasons, I am trying to implement a class SSM which stands for Static Sorted Map in python in order to implement the methods
min_value(self) : find the minimum value
max_value(self) : find the maximum value
search(self, key): to find an element in the list
The list is assumed to be sorted.
Here is the code for the class:
class SSM:
def __init__(self, A):
self.sorted_list = A[:] #the list, assume A is sorted
def min_value(self):
return self.sorted_list[0]
def max_value(self):
return self.sorted_list[-1]
def search(self, K):
def __Bin_Search(s, e, K): # local function # implementation pseudocode
if s == e:
if self.sorted_list[s] == K:
return True, s # return True and position
else:
return False
x = math.ceil((s+e)/2)
if self.sorted_map[x] == K:
return True, x # return True and position
if self.sorted_list[x] > K:
return __Bin_Search(s, x-1, K) # go recursive
else:
return __Bin_Search(x+1, e, K) # go recursive
return __Bin_Search(0, len(self.sorted_list), K) # call __Bin_Search
As you can see from the code, for the method search (self, K) I have an inner function __Bin_Search(s, e, K) which goes recursive on the left or right of the list in order to find the element (it is based on the Binary Search Algorithm).
And so, I expect that the methods search (self, K) returns the result given by __Bin_Search since it is called in the last line.
My problem is that by using search(self, K) nothing is returned.
A = [45, 33, 36, 30, 27, 40, 16, 27]
A.sort()
ssm = SSM(A)
ssm.search(33)
Where is the error in the code? How can I fix that?
Your list always has a length greater than 0 so s will never equal e and therefore never reach a return statement. You need to add a conditional statement in __Bin_Search where s != e.