Thursday, January 2, 2025
Google search engine
HomeData Modelling & AIForm a number using corner digits of powers

Form a number using corner digits of powers

Given two integers N and X. Make a number in such a way that the number contains the first and last digit occurring in N^1, N^2, N^3, .... N^X      .

Examples : 

Input : N = 10, X = 5 
Output : 1010101010
Explanation :
10^1 = 10
10^2 = 100
10^3 = 1000
10^4 = 10000
10^5 = 100000
Take First and Last Digit of each Power to
get required number.

Input : N = 19, X = 4 
Output : 19316911
Explanation :
19^1 = 19
19^2 = 361
19^3 = 6859
19^4 = 130321
Take First and Last Digit of each Power to get required number.

Recommended: Please solve it on “PRACTICE“first, before moving on to the solution.

Approach : 

  1. Calculate all Powers of N from 1 to X one by one. 
  2. Store the Output in power[] array. 
  3. Store power[0] i.e, last_digit and power[power_size – 1] i.e, unit_digit from power[] array to result[] array. 
  4. Print the result[] Array.

Below is the implementation of the above approach :  

C++




// C++ program to find number formed by
// corner digits of powers.
#include <bits/stdc++.h>
using namespace std;
 
// Find next power by multiplying N with
// current power
void nextPower(int N, vector<int> &power)
{
    int carry = 0;
 
    for (int i=0 ; i < power.size(); i++)
    {
        int prod = (power[i] * N) + carry ;
 
        // Store digits of Power one by one.
        power[i] = prod % 10 ;
 
        // Calculate carry.
        carry = prod / 10 ;
    }
 
    while (carry)
    {
        // Store carry in Power array.
        power.push_back(carry % 10);
        carry = carry / 10 ;
    }
}
 
// Prints number formed by corner digits of
// powers of N.
void printPowerNumber(int X, int N)
{
    // Storing N raised to power 0
    vector<int> power;
    power.push_back(1);
 
    // Initializing empty result
    vector<int> res;
 
    // One by one compute next powers and
    // add their corner digits.
    for (int i=1; i<=X; i++)
    {
        // Call Function that store power
        // in Power array.
        nextPower(N, power) ;
 
        // Store unit and last digits of
        // power in res.
        res.push_back(power.back());
        res.push_back(power.front());
    }
 
    for (int i=0 ; i < res.size(); i++)
        cout << res[i] ;
}
 
// Driver Code
int main()
{
    int N = 19 , X = 4;
    printPowerNumber(X, N);
    return 0 ;
}


Java




// Java program to find number formed by
// corner digits of powers.
import java.io.*;
import java.util.*;
  
public class GFG {
     
    static List<Integer> power = new ArrayList<Integer>();
    // Find next power by multiplying N
    // with current power
    static void nextPower(Integer N)
    {
        Integer carry = 0;
      
        for (int i = 0; i < power.size(); i++)
        {
            Integer prod = (power.get(i) * N) + carry ;
      
            // Store digits of Power one by one.
            power.set(i,prod % 10);
      
            // Calculate carry.
            carry = prod / 10 ;
        }
      
        while (carry >= 1)
        {
            // Store carry in Power array.
            power.add(carry % 10);
            carry = carry / 10 ;
        }
    }
      
    // Prints number formed by corner digits of
    // powers of N.
    static void printPowerNumber(int X, int N)
    {
          
        // Storing N raised to power 0
        power.add(1);
      
        // Initializing empty result
        List<Integer> res = new ArrayList<Integer>();
      
        // One by one compute next powers and
        // add their corner digits.
        for (int i = 1; i <= X; i++)
        {
            // Call Function that store power
            // in Power array.
            nextPower(N) ;
      
            // Store unit and last digits of
            // power in res.
            res.add(power.get(power.size() - 1));
            res.add(power.get(0));
        }
      
        for (int i = 0 ; i < res.size(); i++)
            System.out.print(res.get(i)) ;
    }
      
    // Driver Code
    public static void main(String args[])
    {
        Integer N = 19 , X = 4;
        printPowerNumber(X, N);
    }
}
  
// This code is contributed by Manish Shaw
// (manishshaw1)


Python3




# Python3 program to find
# number formed by
# corner digits of powers.
  
# Storing N raised to power 0
power = []
 
# Find next power by multiplying
# N with current power
def nextPower(N) :
    global power
    carry = 0
   
    for i in range(0, len(power)) :
        prod = (power[i] * N) + carry
   
        # Store digits of
        # Power one by one.
        power[i] = prod % 10
   
        # Calculate carry.
        carry = (int)(prod / 10)
   
    while (carry) :
 
        # Store carry in Power array.
        power.append(carry % 10)
        carry = (int)(carry / 10)
   
# Prints number formed by corner
# digits of powers of N.
def printPowerNumber(X, N) :
    global power
    power.append(1)
   
    # Initializing empty result
    res = []
   
    # One by one compute next powers
    # and add their corner digits.
    for i in range(1, X+1) :
 
        # Call Function that store
        # power in Power array.
        nextPower(N)
   
        # Store unit and last
        # digits of power in res.
        res.append(power[-1])
        res.append(power[0])
   
    for i in range(0, len(res)) :
        print (res[i], end="")
   
# Driver Code
N = 19
X = 4
printPowerNumber(X, N)
   
# This code is contributed by
# Manish Shaw(manishshaw1)


C#




// C# program to find number formed by
// corner digits of powers.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Collections;
 
class GFG {
     
    // Find next power by multiplying N
    // with current power
    static void nextPower(int N, ref List<int> power)
    {
        int carry = 0;
     
        for (int i = 0; i < power.Count; i++)
        {
            int prod = (power[i] * N) + carry ;
     
            // Store digits of Power one by one.
            power[i] = prod % 10 ;
     
            // Calculate carry.
            carry = prod / 10 ;
        }
     
        while (carry >= 1)
        {
            // Store carry in Power array.
            power.Add(carry % 10);
            carry = carry / 10 ;
        }
    }
     
    // Prints number formed by corner digits of
    // powers of N.
    static void printPowerNumber(int X, int N)
    {
         
        // Storing N raised to power 0
        List<int> power = new List<int>();
        power.Add(1);
     
        // Initializing empty result
        List<int> res = new List<int>();
     
        // One by one compute next powers and
        // add their corner digits.
        for (int i = 1; i <= X; i++)
        {
            // Call Function that store power
            // in Power array.
            nextPower(N, ref power) ;
     
            // Store unit and last digits of
            // power in res.
            res.Add(power.Last());
            res.Add(power.First());
        }
     
        for (int i = 0 ; i < res.Count; i++)
            Console.Write(res[i]) ;
    }
     
    // Driver Code
    public static void Main()
    {
        int N = 19 , X = 4;
        printPowerNumber(X, N);
    }
}
 
// This code is contributed by Manish Shaw
// (manishshaw1)


PHP




<?php
// PHP program to find
// number formed by
// corner digits of powers.
 
// Find next power by multiplying
// N with current power
function nextPower($N, &$power)
{
    $carry = 0;
 
    for ($i = 0 ; $i < count($power); $i++)
    {
        $prod = ($power[$i] *
                 $N) + $carry ;
 
        // Store digits of
        // Power one by one.
        $power[$i] = $prod % 10 ;
 
        // Calculate carry.
        $carry = (int)($prod / 10) ;
    }
 
    while ($carry)
    {
        // Store carry in Power array.
        array_push($power, $carry % 10);
        $carry = (int)($carry / 10) ;
    }
}
 
// Prints number formed by corner
// digits of powers of N.
function printPowerNumber($X, $N)
{
    // Storing N raised to power 0
    $power = array();
    array_push($power, 1);
 
    // Initializing empty result
    $res = array();
 
    // One by one compute next powers
    // and add their corner digits.
    for ($i = 1; $i <= $X; $i++)
    {
        // Call Function that store
        // power in Power array.
        nextPower($N, $power) ;
 
        // Store unit and last
        // digits of power in res.
        array_push($res,
                   $power[count($power) - 1]);
        array_push($res, $power[0]);
    }
 
    for ($i = 0 ; $i < count($res); $i++)
        echo ($res[$i]) ;
}
 
// Driver Code
$N = 19; $X = 4;
printPowerNumber($X, $N);
 
// This code is contributed by
// Manish Shaw(manishshaw1)
?>


Javascript




<script>
 
// JavaScript program to find number formed by
// corner digits of powers.
 
// Find next power by multiplying N with
// current power
function nextPower(N, power)
{
    var carry = 0;
 
    for (var i=0 ; i < power.length; i++)
    {
        var prod = (power[i] * N) + carry ;
 
        // Store digits of Power one by one.
        power[i] = prod % 10 ;
 
        // Calculate carry.
        carry = parseInt(prod / 10);
    }
 
    while (carry>=1)
    {
        // Store carry in Power array.
        power.push(carry % 10);
        carry = parseInt(carry / 10);
    }
    return power;
}
 
// Prints number formed by corner digits of
// powers of N.
function printPowerNumber( X, N)
{
    // Storing N raised to power 0
    var power = [];
    power.push(1);
 
    // Initializing empty result
    var res = [];
 
    // One by one compute next powers and
    // add their corner digits.
    for (var i=1; i<=X; i++)
    {
        // Call Function that store power
        // in Power array.
        power = nextPower(N, power) ;
 
        // Store unit and last digits of
        // power in res.
        res.push(power[power.length-1]);
        res.push(power[0]);
    }
 
    for (var i=0 ; i < res.length; i++)
        document.write( res[i] );
}
 
// Driver Code
var N = 19 , X = 4;
printPowerNumber(X, N);
 
</script>


Output

19316911

Time Complexity: O(XlogX)

Auxiliary Space: O(N)

Feeling lost in the world of random DSA topics, wasting time without progress? It’s time for a change! Join our DSA course, where we’ll guide you on an exciting journey to master DSA efficiently and on schedule.
Ready to dive in? Explore our Free Demo Content and join our DSA course, trusted by over 100,000 neveropen!

RELATED ARTICLES

Most Popular

Recent Comments