10's Complement of a decimal number

Given a decimal number N. The task is to find 10’s complement of the number N.
Example: 
 

Input : 25
Output : 10's complement is : 75

Input : 456
Output : 10's complement is : 544

10’s complement of a decimal number can be found by adding 1 to the 9's complement of that decimal number. It is just like 2s complement in binary number representation.
Mathematically, 
 

10's complement = 9's complement + 1 
 

For example, let us take a decimal number 456, 9's complement of this number will be 999-456 which will be 543. Now 10s complement will be 543+1=544.
Therefore, 
 

10's complement = 10^len - num 
 

Where, len = total number of digits in num.

 

Below is the program to find 10's complement of a given number: 
 

75
544

Time Complexity: O(logn) where n is the given number

Auxiliary Space: O(1)