Answer:
This program is written in C++
Comment are used to explain difficult lines
The first program that prints 0 to 20 (in decimal) starts here
#include<iostream>
int main()
{
//Print From 0 to 20
for(int i = 0;i<21;i++)
{
std::cout<<i<<'\n';
}
}
The modified program to print 0 to 20 in hexadecimal starts here
#include<iostream>
using namespace std;
int main()
{
//Declare variables to use in conversion;
int tempvar, i=1,remain;
//Declare a char array of length 50 to hold result
char result[50];
//Print 0
cout<<"0"<<endl;
// Iterate from 1 to 20
for(int digit = 1; digit<21; digit++)
{
//Start Conversion Process
//Initialize tempvar to digit (1 to 20)
tempvar = digit;
while(tempvar!=0)
{
//Divide tempvar by 16 and get remainder
remain = tempvar%16;
if(remain<10)
{
result[i++]=remain + 48;
}
else
{
result[i++] = remain + 55;
}
//Get new value of tempvar by dividing it by 16
tempvar/=16;
}
//Print result
for(int l=i-1;l>0;l--)
{
cout<<result[l];
}
i=1;
cout<<endl;
}
return 0;
}
//The Program Ends Here
See Attachments for program 1 and 2; program 2 is the modified version of 1
