Minimum decrements to make integer A divisible by integer B

Given two positive integers A and B where A is greater than B. In one move one can decrease A by 1 which implies that after one move A is equal to A – 1. The task is to find the minimum number of moves required to make A divisible by B in constant time.

Examples:

Input: A = 10, B = 3 
Output: 1
Explanation: Only one move is required A = A – 1 = 9, which is divisible by 3.

Input : A = 10, B = 10
Output : 0
Explanation: Since A is equal to B therefore zero move required. 

Approach:
To solve the problem mentioned above we take the modulus of the numbers that are A % B and the result is stored in a variable that is the required answer.
Below is the implementation of the above approach: 

C++

// C++ implementation to count
// Total numbers moves to make
// integer A divisible by integer B

#include <bits/stdc++.h>
using namespace std;

// Function that print number
// of moves required
void movesRequired(int a, int b)
{
    // calculate modulo
    int total_moves = a % b;

    // print the required answer
    cout << total_moves << "\n";
}

// Driver Code
int main()
{

    // initialise A and B
    int A = 10, B = 3;

    movesRequired(A, B);

    return 0;
}

Java

// Java implementation to count
// total numbers moves to make
// integer A divisible by integer B
import java.util.*;

class GFG{

// Function that print number
// of moves required
static void movesRequired(int a, int b)
{

    // Calculate modulo
    int total_moves = a % b;

    // Print the required answer
    System.out.println(total_moves);
}

// Driver code
public static void main(String[] args)
{

    // Initialise A and B
    int A = 10, B = 3;

    movesRequired(A, B);
}
}

// This code is contributed by offbeat

Python3

# Python3 implementation to count
# total numbers moves to make
# integer A divisible by integer B

# Function that print number
# of moves required
def movesRequired(a, b):

    # Calculate modulo
    total_moves = a % b

    # Print the required answer
    print(total_moves)

# Driver Code
if __name__ == '__main__':

    # Initialise A and B
    A = 10
    B = 3

    movesRequired(A, B)

# This code is contributed by Samarth

C#

// C# implementation to count
// total numbers moves to make
// integer A divisible by integer B
using System;
class GFG
{

// Function that print number
// of moves required
static void movesRequired(int a, int b)
{

    // Calculate modulo
    int total_moves = a % b;

    // Print the required answer
    Console.Write(total_moves);
}

// Driver code
public static void Main(String []args)
{

    // Initialise A and B
    int A = 10, B = 3;

    movesRequired(A, B);
}
}

// This code is contributed by shivanisinghss2110

Javascript

<script>
    // Javascript implementation to count
    // Total numbers moves to make
    // integer A divisible by integer B

    // Function that print number
    // of moves required
    function movesRequired(a, b)
    {
        // calculate modulo
        let total_moves = a % b;

        // print the required answer
        document.write(total_moves);
    }

    // initialise A and B
    let A = 10, B = 3;

    movesRequired(A, B);

// This code is contributed by divyesh072019.
</script>

Output:

1

Time Complexity: O(1), as constant operations are being performed.
Auxiliary Space: O(1), constant space is required for the above approach.