Count Matching Patterns

Problem

Given a string patterns representing the patterns of interest and a string collection representing the collected items, count how many items in collection match the patterns.

Note that the matching is case-sensitive.

Examples

countMatches("cD", "cDcDaa") 
// returns 4
// There are four matches for the
// patterns "c" and "D" in the collection.

countMatches("x", "XXX") 
// returns 0
// The pattern "x" does not match any in the "XXX" collection.