Question

1. A Hogwarts student number starts with a letter and is followed by 4 digits., where the first letter represents the student’s house (G, H, R and S), e.g. G7777, H1234, R4321 and S6666 are all valid. Write a program ValidateHSN that determines whether or not each student number is valid. Display a list of the student numbers and results. e.g. … G77777 invalid H1234 valid HH234 invalid.

e.g. … G77777 invalid

H1234 valid

HH234 invalid

Answer 1

/* I am writing C++ Program using files and I am create one text file

The text file contains (stdnumber.txt)

G7777
H1234
HH234
G77777
R4321
S6666
GG899
S98765
SSS45
H3850
GGGG1

*/

C++ PROGRAM

#include<iostream>
#include<fstream>
using namespace std;

int main()
{
   ifstream in; // Declare ifstream object in
   string s; // declare string object s
   int i; // delcare integer variable i
  
   in.open("D:\\stdnumber.txt"); // read text file "stdnumber.txt" (read mode)
  
   if(!in) // check the file is invalid
   {
       cout<<"Invalid File name"; // display this message
       exit(0); // terminate entire program
   }
  
   while(in>>s) // create while loop for read strings in the file until end of file
   {
   i=1; // initialize i=0
   if(s.length()==5){ // check the string length=5 then,
     
   // check first letter should be G,H,R and S and also check the next character should be in between 0-9 numbers then,
       if((s[0]=='G'||s[0]=='H'||s[0]=='R'||s[0]=='S')&&(s[i]>='0'&&s[i]<='9'))
       {
       cout<<s<<" = valid"<<endl; // display valid string
       i++; // increment i value
  
   }
   else
   cout<<s<<" = invalid"<<endl; // else, display this messaage

   }
  
else
cout<<s<<" = invalid"<<endl; // display if string length!=5

  
  
} // end of while loop

  
  
   return 0;
}

OUTPUT-1

G7777 = valid
H1234 = valid
HH234 = invalid
G77777 = invalid
R4321 = valid
S6666 = valid
GG899 = invalid
S98765 = invalid
SSS45 = invalid
H3850 = valid
GGGG1 = invalid

OUTPUT-2

Invalid File name