Find and Return the sum of two number of Given two Binary String

Samsung Prism - 2021 Interview Question with Solution

1. Given two binary strings, find and return the sum of those two numbers represented by those strings

Ex. num1 = 1001, num2 = 11

Answer to be returned = 1100 (=9(1001) + 3(11) )

Program

def sumofStrings(num1,num2):
    num1 = "0" + num1
    num2 = "0" + num2
    l1 = len(num1)
    l2 = len(num2)
    
    add = ""
    c = 0
    if l2 > l1:
        num1, num2 = num2, num1
        l1, l2 = l2, l1
    i = l1 - 1
    j = l2 - 1
    
    while i >= 0:
        if j >= 0:
            a = int(num1[i]) + int(num2[j]) + c
        else:
            a = int(num1[i]) + c
        
        if a == 0:
            c = 0
            add = "0" + add
        elif a == 1:
            c = 0
            add = "1" + add
        elif a == 2:
            c = 1
            add = "0" + add
        elif a == 3:
            c = 1
            add = "1" + add
        
        i -= 1
        j -= 1
    
    idx = add.index("1")
    return add[idx:]
    
    
sumofStrings('1001','11')

Output

1100

2.Given root of a tree and a key. Find the sum of cousin nodes at that level

Program

def findCousinSum( root, key): 
    if (root == None):  
        return -1
    if (root.data == key): 
        return -1

    currSum = 0
    size = 0
    q = []  
    q.append(root)  
    found = False

    while (len(q)):  
        if (found == True):  
            return currSum  

        size = len(q) 
        currSum = 0

        while (size):  
            root = q[0]  
            q.pop(0)  

            if ((root.left and root.left.data == key) or (root.right and root.right.data == key)) : 
                found = True
            else: 
                if (root.left): 
                    currSum += root.left.data  
                    q.append(root.left)  

                if (root.right) : 
                    currSum += root.right.data  
                    q.append(root.right)  

            size -= 1
    return -1

PS: This Question was Asked By Samsung Prism Internship - 2021