Find Quotient and Remainder of two integer without using division operators

Given two positive integers dividend and divisor, our task is to find quotient and remainder. The use of division or mod operator is not allowed.

Examples:

Input : dividend = 10, divisor = 3 
Output : 3, 1 
Explanation:
The quotient when 10 is divided by 3 is 3 and the remainder is 1.

Input : dividend = 11, divisor = 5 
Output : 2, 1 
Explanation:
The quotient when 11 is divided by 5 is 2 and the remainder is 1. 

Approach:
To solve the problem mentioned above we will use the Binary Search technique. We can implement the search method in range 1 to N where N is the dividend. Here we will use multiplication to decide the range. As soon as we break out of the while loop of binary search we get our quotient and the remainder can be found using the multiplication and subtraction operator. Handle the special case, when the dividend is less than or equal to the divisor, without the use of binary search.

Efficient Approach:

1. Define a function find that takes four parameters – dividend, divisor, start, and end, and returns a pair of integers – quotient and remainder.
2. Check if the start is greater than the end. If yes, return {0, dividend}, where 0 is the quotient and dividend is the remainder.
3. Calculate the mid value as (start + end) / 2.
4. Subtract the product of divisor and mid from the dividend and store it in a variable n.
5. Check if n is greater than divisor. If yes, increment the mid by 1 and update the start to mid+1.
6. Check if n is less than 0. If yes, decrement the mid by 1 and update the end to mid-1.
7. If n is equal to the divisor, increment the mid by 1 and set n to 0.
8. Return the pair {mid, n} as the quotient and remainder.
9. Recursively call the find function with updated values of start and end until start becomes greater than end.
10. Define a function divide that takes two parameters – dividend and divisor, and returns the quotient and remainder using the find function with start = 1 and end = dividend.
11. In the main function, call the divide function with the given values of dividend and divisor, and store the returned pair in a variable ans.
12. Print the quotient and remainder by accessing the first and second elements of ans respectively.

Below is the implementation of the above approach:  

C++

// C++ implementation to Find Quotient
// and Remainder of two integer without
// using / and % operator using Binary search

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

// Function to the quotient and remainder
pair<int, int> find(int dividend, int divisor,
                    int start, int end)
{

    // Check if start is greater than the end
    if (start > end)
        return { 0, dividend };

    // Calculate mid
    int mid = start + (end - start) / 2;

    int n = dividend - divisor * mid;

    // Check if n is greater than divisor
    // then increment the mid by 1
    if (n > divisor)
        start = mid + 1;

    // Check if n is less than 0
    // then decrement the mid by 1
    else if (n < 0)
        end = mid - 1;

    else {
        // Check if n equals to divisor
        if (n == divisor) {
            ++mid;
            n = 0;
        }

        // Return the final answer
        return { mid, n };
    }

    // Recursive calls
    return find(dividend, divisor, start, end);
}

pair<int, int> divide(int dividend, int divisor)
{
    return find(dividend, divisor, 1, dividend);
}

// Driver code
int main(int argc, char* argv[])
{
    int dividend = 10, divisor = 3;

    pair<int, int> ans;

    ans = divide(dividend, divisor);

    cout << ans.first << ", ";
    cout << ans.second << endl;

    return 0;
}

Java

// JAVA implementation to Find Quotient
// and Remainder of two integer without
// using / and % operator using Binary search

class GFG{

// Function to the quotient and remainder
static int[] find(int dividend, int divisor,
                    int start, int end)
{

    // Check if start is greater than the end
    if (start > end)
        return new int[] { 0, dividend };

    // Calculate mid
    int mid = start + (end - start) / 2;

    int n = dividend - divisor * mid;

    // Check if n is greater than divisor
    // then increment the mid by 1
    if (n > divisor)
        start = mid + 1;

    // Check if n is less than 0
    // then decrement the mid by 1
    else if (n < 0)
        end = mid - 1;

    else {
        // Check if n equals to divisor
        if (n == divisor) {
            ++mid;
            n = 0;
        }

        // Return the final answer
        return new int[] { mid, n };
    }

    // Recursive calls
    return find(dividend, divisor, start, end);
}

static int[]  divide(int dividend, int divisor)
{
    return find(dividend, divisor, 1, dividend);
}

// Driver code
public static void main(String[] args)
{
    int dividend = 10, divisor = 3;

    int []ans = divide(dividend, divisor);

    System.out.print(ans[0]+ ", ");
    System.out.print(ans[1] +"\n");

}
}

// This code contributed by sapnasingh4991

Python3

# Python3 implementation to Find Quotient
# and Remainder of two integer without
# using / and % operator using Binary search

# Function to the quotient and remainder
def find(dividend, divisor,  start,  end) :

    # Check if start is greater than the end
    if (start > end) :
        return ( 0, dividend );

    # Calculate mid
    mid = start + (end - start) // 2;

    n = dividend - divisor * mid;

    # Check if n is greater than divisor
    # then increment the mid by 1
    if (n > divisor) :
        start = mid + 1;

    # Check if n is less than 0
    # then decrement the mid by 1
    elif (n < 0) :
        end = mid - 1;

    else :
        # Check if n equals to divisor
        if (n == divisor) :
            mid += 1;
            n = 0;

        # Return the final answer
        return ( mid, n );

    # Recursive calls
    return find(dividend, divisor, start, end);

def divide(dividend, divisor) :

    return find(dividend, divisor, 1, dividend);

# Driver code
if __name__ == "__main__" :

    dividend = 10; divisor = 3;

    ans = divide(dividend, divisor);

    print(ans[0],", ",ans[1])

# This code is contributed by Yash_R

Javascript

<script>

// Javascript implementation to Find Quotient
// and Remainder of two integer without
// using / and % operator using Binary search

// Function to the quotient and remainder
function find(dividend, divisor, start, end)
{

    // Check if start is greater than the end
    if (start > end)
        return [0, dividend];

    // Calculate mid
    var mid = start + parseInt((end - start) / 2);

    var n = dividend - divisor * mid;

    // Check if n is greater than divisor
    // then increment the mid by 1
    if (n > divisor)
        start = mid + 1;

    // Check if n is less than 0
    // then decrement the mid by 1
    else if (n < 0)
        end = mid - 1;

    else
    {

        // Check if n equals to divisor
        if (n == divisor)
        {
            ++mid;
            n = 0;
        }

        // Return the final answer
        return [ mid, n];
    }

    // Recursive calls
    return find(dividend, divisor, start, end);
}

function divide(dividend, divisor)
{
    return find(dividend, divisor, 1, dividend);
}

// Driver code
var dividend = 10, divisor = 3;
var ans = divide(dividend, divisor);

document.write(ans[0] + ", ");
document.write(ans[1] + "\n");

// This code is contributed by gauravrajput1

</script>

C#

// C# implementation to Find Quotient
// and Remainder of two integer without
// using / and % operator using Binary search

using System;

public class GFG{

// Function to the quotient and remainder
static int[] find(int dividend, int divisor,
                    int start, int end)
{

    // Check if start is greater than the end
    if (start > end)
        return new int[] { 0, dividend };

    // Calculate mid
    int mid = start + (end - start) / 2;

    int n = dividend - divisor * mid;

    // Check if n is greater than divisor
    // then increment the mid by 1
    if (n > divisor)
        start = mid + 1;

    // Check if n is less than 0
    // then decrement the mid by 1
    else if (n < 0)
        end = mid - 1;

    else {
        // Check if n equals to divisor
        if (n == divisor) {
            ++mid;
            n = 0;
        }

        // Return the readonly answer
        return new int[] { mid, n };
    }

    // Recursive calls
    return find(dividend, divisor, start, end);
}

static int[]  divide(int dividend, int divisor)
{
    return find(dividend, divisor, 1, dividend);
}

// Driver code
public static void Main(String[] args)
{
    int dividend = 10, divisor = 3;

    int []ans = divide(dividend, divisor);

    Console.Write(ans[0]+ ", ");
    Console.Write(ans[1] +"\n");

}
}
// This code contributed by Princi Singh

Output:

3, 1

Time Complexity: O(logN)
Space Complexity: O(n)

Approach: Brute force approach based on repeated subtraction

One approach to finding the quotient and remainder of two integers without using division or mod operators is by repeated subtraction. The basic idea is to subtract the divisor from the dividend until the dividend becomes less than the divisor. The number of times the subtraction is performed is the quotient, and the final value of the dividend is the remainder.

Here are the steps for this approach:

1. Initialize the quotient to 0 and the remainder to the value of the dividend.
2. While the remainder is greater than or equal to the divisor, subtract the divisor from the remainder and increment the quotient by 1.
3. Return the quotient and remainder.

C++

#include <iostream>
using namespace std;

void findQuotientAndRemainder(int dividend, int divisor, int& quotient, int& remainder) {
    quotient = 0;
    remainder = dividend;

    while (remainder >= divisor) {
        remainder -= divisor;
        quotient += 1;
    }
}

int main() {
    int dividend = 10;
    int divisor = 3;
    int quotient, remainder;

    findQuotientAndRemainder(dividend, divisor, quotient, remainder);

    cout << "Quotient: " << quotient << endl;
    cout << "Remainder: " << remainder << endl;

    return 0;
}

Python3

def find_quotient_and_remainder(dividend, divisor):
    quotient = 0
    remainder = dividend

    while remainder >= divisor:
        remainder -= divisor
        quotient += 1

    return quotient, remainder
dividend = 10
divisor = 3
quotient, remainder = find_quotient_and_remainder(dividend, divisor)
print("Quotient:", quotient)
print("Remainder:", remainder)

Java

// Java program to find quotient and remainder
import java.util.*;

public class Main {

    // Function to find the quotient and
    // remainder
    static void findQuotientAndRemainder(int dividend,
                                         int divisor,
                                         int[] qr)
    {
        qr[0] = 0;
        qr[1] = dividend;
        while (qr[1] >= divisor) {
            qr[1] -= divisor;
            qr[0] += 1;
        }
    }

    // Driver Code
    public static void main(String[] args)
    {
        int dividend = 10;
        int divisor = 3;
        int[] qr = new int[2];

        findQuotientAndRemainder(dividend, divisor, qr);

        System.out.println("Quotient: " + qr[0]);
        System.out.println("Remainder: " + qr[1]);
    }
}

C#

using System;

class Program {
    static void FindQuotientAndRemainder(int dividend, int divisor, out int quotient, out int remainder) {
        quotient = 0;
        remainder = dividend;

        while (remainder >= divisor) {
            remainder -= divisor;
            quotient += 1;
        }
    }

    static void Main(string[] args) {
        int dividend = 10;
        int divisor = 3;
        int quotient, remainder;

        FindQuotientAndRemainder(dividend, divisor, out quotient, out remainder);

        Console.WriteLine("Quotient: {0}", quotient);
        Console.WriteLine("Remainder: {0}", remainder);

        Console.ReadKey();
    }
}

Output

Quotient: 3
Remainder: 1

Time Complexity: O(dividend/divisor)
Auxiliary Space: O(1)