Camelcase Matching

Problem

Given an array of strings queries and a string pattern, return a boolean array answer where answer[i] is true if queries[i] matches pattern, and false otherwise.

A query word queries[i] matches pattern if you can insert lowercase English letters pattern so that it equals the query. You may insert each character at any position and you may not insert any characters.

Examples

Example 1:

Input: queries = ["FooBar","FooBarTest","FootBall","FrameBuffer","ForceFeedBack"], pattern = "FB"
Output: [true,false,true,true,false]
Explanation: "FooBar" can be generated like this "F" + "oo" + "B" + "ar".
"FootBall" can be generated like this "F" + "oot" + "B" + "all".
"FrameBuffer" can be generated like this "F" + "rame" + "B" + "uffer".

Example 2:

Input: queries = ["FooBar","FooBarTest","FootBall","FrameBuffer","ForceFeedBack"], pattern = "FoBa"
Output:
 [true,false,true,false,false]
Explanation: "FooBar" can be generated like this "Fo" + "o" + "Ba" + "r".
"FootBall" can be generated like this "Fo" + "ot" + "Ba" + "ll".

Example 3:

Input: queries = ["FooBar","FooBarTest","FootBall","FrameBuffer","ForceFeedBack"], pattern = "FoBaT"
Output: [false,true,false,false,false]
Explanation: "FooBarTest" can be generated like this "Fo" + "o" + "Ba" + "r" + "T" + "est".

Solution

Method 1 - Iterating Over Chars with 2 Pointers on Query and Pattern

Code

Java

public List<Boolean> camelMatch(String[] queries, String pattern) {
	return Arrays.stream(queries).map(q -> isMatch(q, pattern)).collect(Collectors.toList());
}

public boolean isMatch(String query, String pattern) {
	int j = 0; // j for pattern and i for query
	for(int i = 0; i < query.length(); i++) {
		char c = query.charAt(i);
		if(j < pattern.length() && pattern.charAt(j) == c) {
			j++;
		}else if(Character.isUpperCase(c)) {
			return false;
		}
	}
	return j == pattern.length();
}