A computer shop assembles desktop computers, using items bought from several suppliers. A text file Stock.txt contains information about each item. Information for each item is stored as a single line in the Stock.txt file in the format: <ItemNum><SupplierCode><Description> Item information is as follows: | | Format | Comment | |:---|:---|:---| | ItemNum | 4 numeric characters | unique number for each item in the range "0001” to "5999" inclusive | | SupplierCode | 3 alphabetic characters | code to identify the supplier of the item | | Description | a string | a minimum of 12 characters | The file is organised in ascending order of ItemNum and does not contain all possible values in the range. The programmer has defined the first program module as follows: | Module | Description | |:---|:---| | ChangeSupp() | • called with two parameters Code1 and Code2 of type string that represent valid supplier codes | • creates a new file NewStock.txt from the contents of the file Stock.txt where any reference to Code1 is replaced by Code2 | • returns a count of the number of items that have had their supplier code changed |