Question

Write a program in c++ using only while and for loops . Use of arrays and functions is not allowed.

Given the first value, generate the next ten terms of the sequence like 1, 2, 4, 8, 16, 22, 26,
38, 62, 74, 102, 104, …

Explaination with code is required.

Answer 1

C++ code

#include <iostream>
using namespace std;

int main() {
  
   int start ;
   //takes the starting number of sequence
   cout<<" Enter the first term of sequence "<<endl;
   cin>>start;
   int i ;
   //for loop as prescribed to use
   for( i = 0 ; i < 10 ; i++ ){
       //storing the element
       int prev = start ;
       //printing the newly calculated element of sequence
       cout<< start << ", ";
       int add = 1;
       //while loop as prescribed to use
       //logic
       // adding the number and the product of non-zero digits
       while( start != 0 ){
           //checking if the digit is zero or not
           int r = start%10;
           if( r != 0 ){
               //so that this is the new value to add into element
               add *= r;
           }
           //parsing every digit
           start = start/10;
       }
       //adding new value to the element and getting new element of sequence
       start = prev + add ;
   }
   //end of for loop
   return 0;
}

Output

74 as first term

 Enter the first term of sequence 
74, 102, 104, 108, 116, 122, 126, 138, 162, 174, 

1 as first term

 Enter the first term of sequence 
1, 2, 4, 8, 16, 22, 26, 38, 62, 74, 

202 as first term

 Enter the first term of sequence 
202, 206, 218, 234, 258, 338, 410, 414, 430, 442,