Pattern Matching Problem

pattern.matching.js

/*  Given a pattern and a string input - find if  the string follows the same pattern and return 0 or 1. Examples: 1) Pattern : "abba", input: "redblueredblue" should return 1. 2) Pattern: "aaaa", input: "asdasdasdasd" should return 1. 3) Pattern: "aabb", input: "xyzabcxzyabc" should return 0. */


const isMatch = (pat, str) => {

    if (pat.length === 0 || str.len === 0) return false;


    for (let i = 0; i <= str.length; i++) {

        let activeStr = str.substring(0, i);
        for (let j = i; j <= str.length; j++) {
            for (let k = j; k <= str.length; k++) {
                let subactiveStr = str.substring(j, k);
                let genPattern = generatePattern(activeStr, subactiveStr, pat);
                //console.log(genPattern);
                if (genPattern === str) {
                    //console.log(`~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~`);
                    //console.log(`Left: ${activeStr}, Right: ${subactiveStr}`);
                    return true;
                }
            }
        }


    }

    return false;
    
}


const generatePattern = (left, right, pattern) => {
    
    if (left === `` || right === ``)
        return ``;
    
    else {
        console.log(`${left}:${right}`);
    }

    let result = ``;
    let start = pattern[0];
    for (let c of pattern) {
        if (c == start)
            result += left;
        else 
            result += right;
    }
    return result;
}

console.log(isMatch(`baba`, `redblueredblue`));