https://leetcode.com/problems/camelcase-matching/

camelCaseMathing.js

/**
 * @param {string[]} queries
 * @param {string} pattern
 * @return {boolean[]}
 */
// O(n) but massively overcomplicated. 
var camelMatch = function(queries, pattern) {
    
    const pCapSegments = capitalSegments(pattern);
    
    return queries.map((q) => { // Could have done a single pass here with two pointers ='(
       
        const qCapSegments = capitalSegments(q); // ['', 'Foo', 'Bar', 'T'] || ['oo', 'Boo', 'T']
        
        if(qCapSegments.length !== pCapSegments.length) return false; // number of caps must match
        
        for(let i=0; i<pCapSegments.length; i++){ // for each capital segment
            
            const firstPCapChar = pCapSegments[i][0] || '';
            const firstQCapChar = qCapSegments[i][0] || '';
            
            if((firstPCapChar && (firstPCapChar.toUpperCase() === firstPCapChar)) ||
               (firstQCapChar && (firstQCapChar.toUpperCase() === firstQCapChar))){ // if either is capital
                if(firstPCapChar !== firstQCapChar) return false; // the capitals must match
            }
            
            // and the remainder of the query must be a subsequence of the remainder of the pattern
            const [a, b] = [pCapSegments[i].replace(/[A-Z]/g, ''), qCapSegments[i].replace(/[A-Z]/g, '')]
            const sub =  isSubsequence(a, b);

            if(!sub) return false;
        }
        
        return true;
    });
  
    function isSubsequence(a, b){ // returns true if A is a subsequence of B
        
        if(a.length > b.length) return false; // subsequence cannot be longer than sequence
        if(!a.length) return true; // empty string is always a subsequence of anything
        
        let aIndex = 0;
        
        for(let bIndex = 0; bIndex < b.length; bIndex++){
            if(b[bIndex] === a[aIndex]){
                aIndex++;
                if(aIndex === a.length) return true;
            }
        }
        
        return false;
    }
    
    function capitalSegments(str){
        const result = [];
        let current = [''];
        
        for(let i=0; i<str.length; i++){
            if(str[i].toUpperCase() === str[i]){
                result.push(current.join(''));
                current = [str[i]];
            }else{
                current.push(str[i]);
            }
        }
        
        if(current.length) result.push(current.join(''))
        
        return result;
    }
};