HW5: String

1. Use the find() function to design an occurrence function, which will count the number of occurrences of a string in a text.
   • int occurrence(string text, string str);
2. Try to use a long text to test your function.
3. Modify your function so that it is case-insensitive (i.e., both "ABC" and "aBc" matches "abc").
4. Be sure to submit a CPP source file instead of a compressed file.