algorithms_python

Binary Search

def binarySearch(numbers, low, high, x):
    if (high >= low):
        mid = low + (high - low)//2
        if (numbers[mid] == x):
            return mid
        elif (numbers[mid] > x):
            return binarySearch(numbers, low, mid-1, x)
        else:
            return binarySearch(numbers, mid+1, high, x)
    else:
        return -1
numbers = [ 1,4,6,7,12,17,25 ]   #binary search requires sorted numbers
x = 7
result = binarySearch(numbers, 0, len(numbers)-1, x)
if (result != -1):
    print("Search successful, element found at position ", result)
else:
    print("The given element is not present in the array")

Selected Sort

  
  def selectSort(A):
    for i in range(len(A)):
        min=i
        for j in range(i+1,len(A)):
            if A[min]>A[j]:
                min=j
        A[i],A[min]=A[min],A[i]
  

Bubble Sort

  
  def bubbleSort(arr):
    n=len(arr):
    for i in range(n):
        swapped=False
        for j in range(0,n-i-1):
            if arr[j]>arr[j+1]:
                arr[j],arr[j+1]=arr[j+1],arr[j]
                swapped=True
        if swapped==False:
            break