Sample Interactive Session 2 (with deletes)

% cat licences
UBT878 1
KGB209 1
TEA311 3
MUK772 1
XYZ333 2
% cc -o hash hash.c license.c
% hash
  0:    NULL
  1:    NULL
  2:    NULL
  3: license: UBT878, num: 1, hash(license):  3
  4: license: KGB209, num: 1, hash(license):  4
  5: license: TEA311, num: 3, hash(license):  4
  6: license: MUK772, num: 1, hash(license):  5
  7: license: XYZ333, num: 2, hash(license):  3
  8:    NULL
  9:    NULL
 10:    NULL
 11:    NULL
 12:    NULL
Enter license number (or "quit" or "delete") ---> delete
Enter license number to delete ---> ABC234
Number: "ABC234" not present, can't delete
  1:    NULL
  2:    NULL
  3: license: UBT878, num: 1, hash(license):  3
  4: license: KGB209, num: 1, hash(license):  4
  5: license: TEA311, num: 3, hash(license):  4
  6: license: MUK772, num: 1, hash(license):  5
  7: license: XYZ333, num: 2, hash(license):  3
  8:    NULL
  9:    NULL
 10:    NULL
 11:    NULL
 12:    NULL
Enter license number (or "quit" or "delete") ---> delete
Enter license number to delete ---> TEA311
  0:    NULL
  1:    NULL
  2:    NULL
  3: license: UBT878, num: 1, hash(license):  3
  4: license: KGB209, num: 1, hash(license):  4
  5:    DELETED
  6: license: MUK772, num: 1, hash(license):  5
  7: license: XYZ333, num: 2, hash(license):  3
  8:    NULL
  9:    NULL
 10:    NULL
 11:    NULL
 12:    NULL
Enter license number (or "quit" or "delete") ---> XYZ333
The 3rd time for license: XYZ333
  0:    NULL
  1:    NULL
  2:    NULL
  3: license: UBT878, num: 1, hash(license):  3
  4: license: KGB209, num: 1, hash(license):  4
  5:    DELETED
  6: license: MUK772, num: 1, hash(license):  5
  7: license: XYZ333, num: 3, hash(license):  3
  8:    NULL
  9:    NULL
 10:    NULL
 11:    NULL
 12:    NULL
Enter license number (or "quit" or "delete") ---> KGB209
The 2nd time for license: KGB209
  0:    NULL
  1:    NULL
  2:    NULL
  3: license: UBT878, num: 1, hash(license):  3
  4: license: KGB209, num: 2, hash(license):  4
  5:    DELETED
  6: license: MUK772, num: 1, hash(license):  5
  7: license: XYZ333, num: 3, hash(license):  3
  8:    NULL
  9:    NULL
 10:    NULL
 11:    NULL
 12:    NULL
Enter license number (or "quit" or "delete") ---> delete
Enter license number to delete ---> KGB209
  0:    NULL
  1:    NULL
  2:    NULL
  3: license: UBT878, num: 1, hash(license):  3
  4:    DELETED
  5:    DELETED
  6: license: MUK772, num: 1, hash(license):  5
  7: license: XYZ333, num: 3, hash(license):  3
  8:    NULL
  9:    NULL
 10:    NULL
 11:    NULL
 12:    NULL
Enter license number (or "quit" or "delete") ---> MUK772
The 2nd time for license: MUK772
  0:    NULL
  1:    NULL
  2:    NULL
  3: license: UBT878, num: 1, hash(license):  3
  4:    DELETED
  5:    DELETED
  6: license: MUK772, num: 2, hash(license):  5
  7: license: XYZ333, num: 3, hash(license):  3
  8:    NULL
  9:    NULL
 10:    NULL
 11:    NULL
 12:    NULL
Enter license number (or "quit" or "delete") ---> quit
% cat licenses.txt
UBT878 1
MUK772 2
XYZ333 3