Adding Large Numbers as Strings | Dataford Interview Questions

If you have two strings that each contain a number larger than 32-bit, how would you add them and return the result as a string?

Implement add_strings(num1, num2), where both parameters are strings containing nonnegative decimal integers, and return their exact sum as a string without converting either input to a built-in integer. Inputs contain no leading zeros unless the value is "0".

Examples: "456" + "789" returns "1245"; "99999999999999999999" + "1" returns "100000000000000000000".

Constraints

1 <= len(num1), len(num2) <= 1000
num1 and num2 contain only decimal digits
Neither input has leading zeros unless its value is "0"
The inputs may represent values larger than 32-bit integer limits
Do not convert either complete input to an integer

Function Signature

def add_strings(num1, num2):

Your question is Adding Large Numbers as Strings. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem

If you have two strings that each contain a number larger than 32-bit, how would you add them and return the result as a string?

Examples: "456" + "789" returns "1245"; "99999999999999999999" + "1" returns "100000000000000000000".

Constraints

1 <= len(num1), len(num2) <= 1000
num1 and num2 contain only decimal digits
Neither input has leading zeros unless its value is "0"
The inputs may represent values larger than 32-bit integer limits
Do not convert either complete input to an integer

Function Signature

def add_strings(num1, num2):

Your question is Adding Large Numbers as Strings. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.