Program to convert a decimal number into its corresponding octal binary hexadecimal number

Answer 1

Don't copy! but learn from this code:
https://code.sololearn.com/cW3O7q0ULqYs/?ref=app

Answer 2

two variants using c printf and C++ ostream functionality. if you use the corresponding sprintf or stringstream you can assign the output to a variable.
https://code.sololearn.com/cvnT36tvdWyw/?ref=app