Question

Write a C++ program that produces a bar chart showing the yearly income
of a small company starting 1990. The program reads the income figures (rounded to
the nearest $1,000) from a file called “income.txt”. For each year it should display the
date and a bar consisting of one star („*‟) for each $1,000.
Here is an example of how the chart might begin:
1990 **
1991 ****
1992 ***
1993 *****
Your program must have 2 functions: one function to get the length of the bar for a
given year and the other function draws one line of the chart.

Answer 1

#include <iostream>
#include <fstream>
#include <string>
 
using namespace std;
 
 
bool exists(string fileName)
{
       bool ok = false;
       ifstreamfile(fileName);
       if (file.good())
       {
             ok= true;
             file.close();
       }
       return ok;
}
 
 
int maxDigit(unsigned long int d)
{
       int m = 0;
       while (d > 0)
       {
             if (d % 10 > m)
             {
                    m= d % 10;
             }
             d/= 10;
       }
       return m;
}
 
 
int countDigit(unsigned long int d)
{
       int c = 0;
       do
       {
             c++;
             d/= 10;
       }while (d > 0);
       return c;
}
 
 
void buildHistogram(unsigned long int id, int digits[]) {
       int maxd = maxDigit(id);
       int len = countDigit(id);
       for (int i = 1; i <= len; i++)
       {
             digits[len- i] = id % 10;
             id/= 10;
       }
}
 
 
void writeHistogram(ostream& os, unsigned long int id, int digits[])
{
       int rows = maxDigit(id);
       int len = countDigit(id);
 
       os<< id << endl;
       for (int i = 0; i < rows; i++)
       {
             for (int j = 0; j < len; j++)
             {
                    if (digits[j] > i)
                    {
                          os<< '*';
                    }
                    else
                    {
                          os<< ' ';
                    }
             }
             os<< endl;
       }
}
 
 
int main()
{
       stringfileName;
       stringchoice;
       ifstreaminputFile;
       ofstreamoutputFile;
       unsigned long int id;
       int digits[20];
 
       /* Section 1 */
       cout<< "Pleaseenter the name of the file you wish to open : ";
       cin>> fileName;
       inputFile.open(fileName);
       if (inputFile.fail())
       {
             cout<< "Cannot open input file with such name." << endl;
             return 1;
       }
       cout<< "Thefile is successfully opened." << endl;
 
       /* Section 2 */
       do {
             cout<< "Pleaseenter the name of the file you wish to write : ";
             cin>> fileName;
             if (exists(fileName))
             {
                    cout<< "Afile "<< fileName << "exists." << endl;
                    cout<< "Doyou want to continue and overwrite it? (y/n) : ";
                    cin>> choice;
                    if (choice == "y")
                    {
                          outputFile.open(fileName);
                    }
             }
             else {
                    outputFile.open(fileName);
                    if (!outputFile.good())
                    {
                          cout<< "Cannot open/create output file with such name." << endl;
                          return 1;
                    }
             }
       }while (!outputFile.good());
       cout<< "Thefile is successfully opened." << endl << endl;
 
       /* Section 3 */
       inputFile>> id;
       buildHistogram(id,digits);
 
       /* Section 4 */
       writeHistogram(outputFile,id, digits);
       writeHistogram(cout,id, digits);
 
       /* Section 5 */
       inputFile.close();
       outputFile.close();
 
       return 0;
}