Program to Count numbers on fingers

Count the given numbers on your fingers and find the correct finger on which the number ends. 

Examples:

Input : 17
Output :1

Input :27
Output :3

Approach: The first number starts from the thumb, second on the index finger, third on the middle finger, fourth on the ring finger, and fifth on the little finger.

• Again six comes on the ring finger and so on.
• Here we observer a pattern, 8(last number) and 2 ends up in 2nd position, 3rd or 7th on the middle finger, and so on.
• The pattern keeps repeating after every 8 numbers
  • 1 to 8
  • 9 to 16
  • 17 to 24, and so on
    

Java

// Java Program to Count numbers on fingers
class GFG
{
static int count_num_finger(int n)
{
    int r = n % 8;
    if (r == 0)
        return 2;
    if (r < 5)
        return r;
    else
        return 10 - r;
}

// Driver Code
public static void main(String[] args)
{
    int n;
    n = 30;
    System.out.println(count_num_finger(n));
}
}

// This code is contributed
// by Mukul Singh

Python3

def count_num_finger( n ):
    r = n % 8
    if r == 0:
        return 2
    if r < 5:
        return r
    else:
        return 10 - r

# Driver Code
n = 30
print(count_num_finger(n))

# This code is contributed by "Sharad_Bhardwaj".

Javascript

<script>
    // Javascript Program to Count numbers on fingers

    function count_num_finger(n)
    {
        let r = n % 8;
        if (r == 0)
            return 2;
        if (r < 5)
            return r;
        else
            return 10 - r;
    }

    let n;
    n = 30;
    document.write(count_num_finger(n));

// This code is contributed by mukesh07.
</script>

PHP

<?php
function count_num_finger( $n )
{
    $r = $n % 8;
    if ($r == 2)
        return 0;
    if ($r < 5)
        return $r;
    else
        return 10 - $r;
}

// Driver Code
$n = 30;
echo(count_num_finger($n));

// This code is contributed
// by Aman Ojha
?>

Output

4

Time Complexity: O(1), As we are doing only constant time operations.
Auxiliary Space: O(1), As constant extra space is used.

Asked in Paytm Campus Placement August 2017 

#Example:2

C++

#include <iostream>
using namespace std;

// function to count fingers
int countFingers(int n)
{
  // calculate the number of full hands
  int full_hands = n / 10;

  // calculate the number of fingers used in full hands
  int full_fingers = full_hands * 10;

  // calculate the number of remaining fingers
  int remaining_fingers = n % 10;

  // calculate the total number of fingers used
  int total_fingers = full_fingers + remaining_fingers;

  // return the total number of fingers used
  return total_fingers;
}

// Driver code
int main()
{
  int n = 23;
  int total_fingers = countFingers(n);
  cout << "Total number of fingers used to count " << n
    << " is " << total_fingers << endl;

  return 0;
}

// This code is contributed by user_dtewbxkn77n

Java

import java.util.*;

public class Gfg {

    // function to count fingers
    public static int countFingers(int n) {
        // calculate the number of full hands
        int full_hands = n / 10;

        // calculate the number of fingers used in full hands
        int full_fingers = full_hands * 10;

        // calculate the number of remaining fingers
        int remaining_fingers = n % 10;

        // calculate the total number of fingers used
        int total_fingers = full_fingers + remaining_fingers;

        // return the total number of fingers used
        return total_fingers;
    }

    // Driver code
    public static void main(String[] args) {
        int n = 23;
        int total_fingers = countFingers(n);
        System.out.println("Total number of fingers used to count " + n
            + " is " + total_fingers);
    }
}

Python3

# program to count numbers on fingers

def count_fingers(n):
    # calculate the number of full hands
    full_hands = n // 10

    # calculate the number of fingers used in full hands
    full_fingers = full_hands * 10

    # calculate the number of remaining fingers
    remaining_fingers = n % 10

    # calculate the total number of fingers used
    total_fingers = full_fingers + remaining_fingers

    # return the total number of fingers used
    return total_fingers

# example usage
n = 23
total_fingers = count_fingers(n)
print("Total number of fingers used to count", n, "is", total_fingers)

Javascript

// JavaScript equivalent of the Python code
// Define a function to count fingers
function count_fingers(n) {
// Calculate the number of full hands
let full_hands = Math.floor(n / 10);
// Calculate the number of fingers used in full hands
let full_fingers = full_hands * 10;

// Calculate the number of remaining fingers
let remaining_fingers = n % 10;

// Calculate the total number of fingers used
let total_fingers = full_fingers + remaining_fingers;

// Return the total number of fingers used
return total_fingers;
}

// Example usage
let n = 23;
let total_fingers = count_fingers(n);
console.log('Total number of fingers used to count '+n+' is' + total_fingers);

C#

using System;

class Program {
    static int CountFingers(int n) {
        // calculate the number of full hands
        int fullHands = n / 10;

        // calculate the number of fingers used in full hands
        int fullFingers = fullHands * 10;

        // calculate the number of remaining fingers
        int remainingFingers = n % 10;

        // calculate the total number of fingers used
        int totalFingers = fullFingers + remainingFingers;

        // return the total number of fingers used
        return totalFingers;
    }

    static void Main(string[] args) {
        int n = 23;
        int totalFingers = CountFingers(n);
        Console.WriteLine("Total number of fingers used to count {0} is {1}", n, totalFingers);
    }
}

Output

Total number of fingers used to count 23 is 23

Approach:

1.Define a function count_fingers that takes an integer n as input. The function will return the total number of fingers used to count up to n.
2.Calculate the number of full hands needed to count up to n by dividing n by 10 and using integer division to round down to the nearest whole number. Assign this value to the variable full_hands.
3.Calculate the number of fingers used in the full hands by multiplying full_hands by 10. Assign this value to the variable full_fingers.
4.Calculate the number of remaining fingers needed to count up to n after using all full hands by taking the remainder of n divided by 10. 5.Assign this value to the variable remaining_fingers.
6.Calculate the total number of fingers used to count up to n by adding full_fingers and remaining_fingers. Assign this value to the variable total_fingers.
7.Return the total_fingers value.
8.In the example usage, create an integer n and call the count_fingers function with this argument. Finally, print the total number of fingers used to count up to n.

Time complexity: O(1).

Space complexity: O(1).