Question

Write a program that prompts a user for an integer from 1 to 99 and prints it as an amount in words.  
The program will loop in case the user wants to input an additional number.
If the user enters -99, the program will exit.

Example:
Input: 89
Output: Eighty nine

Input: 45
Output: Fourty five

Input: -99
Output: Have a nice day.
<program exits>

c++ project. need help.

Answer 1

#include <iostream>
#include <limits>

using namespace std;

int digitsInNumber; // global variable to store 
bool validNumber(int); // function to check whether entered number is single digit or two digit
void isSingleDigit(int);//if number is single digit
void lessThan19(int); // if number is two digit and less than 19
void greaterThan19(int);// if number is two digit and greater than 10
int main()
{
    int n=0; // to store user entered number
    bool reEnter=true;// to check whether entered number is valid i.e 1-99 or -99
    bool whetherInteger=true;
    // this loop will take input from user and check whether number is between 1-99 or -99
    do{
        cin>>n;
        if(!cin) //if value is not integer
        {
          cin.clear();
          cin.ignore(numeric_limits<streamsize>::max(), '\n');
          whetherInteger=false;
          
        }
        else //if value is integer
        {
            if((n>0 &&n<100)|| n==-99)
            {
              reEnter=false;
            }
        }
    }while(reEnter==1);

    // loop to calculate number of digits in the user entered number
    int temp=n;
    int count=0;
    while (temp != 0) { 
       temp = temp / 10; 
        ++count;
        digitsInNumber=count;
    }
    
    // for our output there are 4 cases
    // case1: when number is -99
    // case2: when number is between 1-9
    // case3: when number is between 10-19
    // case4: when number is between 20-99
    // if number is -99 output will be "have a nice day"
    if(n==-99) // case 1
    {
      cout<<"Have a nice day";
    } 
    else
    {
      if(digitsInNumber==1) // case 2
      {
        isSingleDigit(n);
      }
      if(digitsInNumber==2)
      {
        if(n<20) //case 3
        {
          lessThan19(n);
        }
        else // case 4
        {
          greaterThan19(n); 
        }
      }
  }
    return 0;
}
// This method will run single digit number 
// it will take number as argument and will print specific word
void isSingleDigit(int n)
  {
    switch(n)
    {
      case 1:cout<<"one ";break;
      case 2:cout<<"two ";break;
      case 3:cout<<"three ";break;
      case 4:cout<<"four ";break;
      case 5:cout<<"five ";break;
      case 6:cout<<"six ";break;
      case 7:cout<<"seven ";break;
      case 8:cout<<"eight ";break;
      case 9:cout<<"nine ";break;
    }
  }

// This method will run two digit number from 10-19
// it will take number as argument and will print specific word
  void lessThan19(int n)
  {
    switch(n)
    {
      case 10:cout<<"ten";break;
      case 11:cout<<"eleven ";break;
      case 12:cout<<"twelve ";break;
      case 13:cout<<"thirteen ";break;
      case 14:cout<<"fourteen ";break;
      case 15:cout<<"fifteen ";break;
      case 16:cout<<"sixteen ";break;
      case 17:cout<<"seventeen ";break;
      case 18:cout<<"eighteen ";break;
      case 19:cout<<"nineteen ";break;
    
    }
  }

  // This method will take number from 20-99
  // we have similarities in these numbers
  // Their 10's place digit are same for 10 numbers
  void greaterThan19(int n)
  {
    int digit1=n%10; // unit place of number
    n=n/10;
    int digit0=n%10; //  10's place of number
    // for digit 0 we can use specific words and for digit we call the method same as thaf of single digit number
    switch(digit0) 
    {
      case 2:cout<<"twenty ";break;
      case 3:cout<<"thirty ";break;
      case 4:cout<<"fourty ";break;
      case 5:cout<<"fifty ";break;
      case 6:cout<<"sixty ";break;
      case 7:cout<<"seventy ";break;
      case 8:cout<<"eighty ";break;
      case 9:cout<<"ninety ";break;
    }
    if(digit1>0)
    {
      isSingleDigit(digit1);
    }
  }