# 10’s Complement of a decimal number

Last Updated : 01 Sep, 2022

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

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

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

10â€™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 = 10len – num

Where, len = total number of digits in num.

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

## C++

 // C++ program to find 10's complement   #include #include   using namespace std;   // Function to find 10's complement int complement(int num) {     int i,len=0,temp,comp;           // Calculating total digits     // in num     temp = num;     while(1)     {         len++;         num=num/10;         if(abs(num)==0)             break;            }           // restore num     num = temp;           // calculate 10's complement     comp = pow(10,len) - num;           return comp; }   // Driver code int main() {     cout<

## Java

 // Java program to find 10's complement import java.io.*;   class GFG { // Function to find 10's complement static int complement(int num) {     int i, len = 0, temp, comp;           // Calculating total     // digits in num     temp = num;     while(true)     {         len++;         num = num / 10;         if(Math.abs(num) == 0)             break;     }           // restore num     num = temp;           // calculate 10's complement     comp = (int)Math.pow(10,len) - num;           return comp; }   // Driver code public static void main (String[] args) {     System.out.println(complement(25));           System.out.println(complement(456)); } }   // This code is contributed // by chandan_jnu.

## Python3

 # Python3 program to find # 10's complement import math   # Function to find 10's complement def complement(num):     i = 0;     len = 0;     comp = 0;           # Calculating total     # digits in num     temp = num;     while(1):         len += 1;         num = int(num / 10);         if(abs(num) == 0):             break;           # restore num     num = temp;           # calculate 10's complement     comp = math.pow(10, len) - num;           return int(comp);   # Driver code print(complement(25)); print(complement(456));   # This code is contributed by mits

## C#

 // C# program to find // 10's complement using System;   class GFG { // Function to find 10's complement static int complement(int num) {     int len = 0, temp, comp;           // Calculating total     // digits in num     temp = num;     while(true)     {         len++;         num = num / 10;         if(Math.Abs(num) == 0)             break;     }           // restore num     num = temp;           // calculate 10's complement     comp = (int)Math.Pow(10, len) - num;           return comp; }   // Driver code public static void Main () {     Console.WriteLine(complement(25));           Console.WriteLine(complement(456)); } }   // This code is contributed // by chandan_jnu.



## Javascript



Output:

75
544

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

Auxiliary Space: O(1)