Example:2
Write a python script to search an element with in a list using Binary Search.(Create a user defined list)
Sol:
def binary_search(arr, x):
low = 0
high = len(arr) - 1
mid = 0
while low <= high:
mid = (high + low) // 2
# Check if x is present at mid
if arr[mid] < x:
low = mid + 1
# If x is greater, ignore left half
elif arr[mid] > x:
high = mid - 1
# If x is smaller, ignore right half
else:
return mid
# If we reach here, then the element was not present
return -1
#-- main --
# create a user defined list
arr=[]
while True:
a=int(input("Enter the element to add "))
arr.append(a)
ch=input("Like to cont (y/n) ")
if(ch=="y" or ch=="Y"):
continue;
else:
break
#to display the list
print(arr)
#to sort the elements of the list arr
arr.sort()
#condition for binary search is elements should be sorted
print("Sorted list")
print(arr)
x=int(input("Enter the element to search "))
# Function call
result = binary_search(arr, x)
if result != -1:
print("Element is present at index", str(result)," position = ",str(result+1))
else:
print("Element is not present in array")
Output:
Enter the element to add 10 Like to cont (y/n) y Enter the element to add 25 Like to cont (y/n) y Enter the element to add 96 Like to cont (y/n) y Enter the element to add 4 Like to cont (y/n) y Enter the element to add 65 Like to cont (y/n) n [10, 25, 96, 4, 65] Sorted list [4, 10, 25, 65, 96] Enter the element to search 25 Element is present at index 2 position = 3
