# Program to find the last digit of X in base Y

• Last Updated : 08 Mar, 2022

Given a positive integer X and Y, the task is to find the last digit of X in the given base Y.

Examples:

Input: X = 10, Y = 7
Output: 3
10 is 13 in base 9 with last digit 3

Input: X = 55, Y = 3
Output: 1
55 is 3 in base 601 with last digit 1

Approach:

• When we try to convert X into the base Y
• We repeatedly divide X by base Y and store the remainder.
• So final result comprises of the remainders in the order of division steps.
• Lets say the remainder of division step 1 is p, step 2 is q, step 3 is r
• Then the resultant number in base Y will be rqp
• And the last digit will be p
• Therefore, we just need to find the first remainder of X when divided by Y to get the last digit in X in base Y.

last digit = X % Y

Below is the implementation of the above approach:

## C++

 // C++ Program to find// the last digit of X in base Y #include using namespace std; // Function to find the last// digit of X in base Yvoid last_digit(int X, int Y){    cout << X % Y;} // Driver codeint main(){    int X = 55, Y = 3;    last_digit(X, Y);    return 0;}

## Java

 // Java Program to find// the last digit of X in base Yclass GFG{ // Function to find the last// digit of X in base Ystatic void last_digit(int X, int Y){    System.out.print(X % Y);} // Driver codepublic static void main(String []args){    int X = 55, Y = 3;    last_digit(X, Y);}} // This code is contributed by Rajput-Ji

## Python3

 # Python3 Program to find# the last digit of X in base Y # Function to find the last# digit of X in base Ydef last_digit(X, Y) :     print(X % Y); # Driver codeif __name__ == "__main__" :     X = 55; Y = 3;    last_digit(X, Y); # This code is contributed# by AnkitRai01

## C#

 // C# Program to find the last digit// of X in base Yusing System; class GFG{ // Function to find the last// digit of X in base Ystatic void last_digit(int X, int Y){    Console.Write(X % Y);} // Driver codepublic static void Main(String []args){    int X = 55, Y = 3;    last_digit(X, Y);}} // This code is contributed by Rajput-Ji



## Javascript


Output:
1

Time Complexity: O(1)

Auxiliary Space: O(1)

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