Program to return the shortest balanced fragment of a string

shortest_balanced_fragment.js

// Author: Safiq Lodi
//Goal: To find the shortest balanced fragment in a string.

/*
    A balanced string that has equal number of lower and upper case characters.
    For example - AaBb is a balanced string but TacoCat is not.

*/ 


const lower = 'lower';
const upper = 'upper';
// const string = 'TACOtacoshgdhjsgdhshdgsghdfghsfdAAaamsdAasdhshdgh';
// const string = 'AbcdefghijklmonopqrstuvwxyzaabbAsjshdghsdghsgdABDbda';
const string = 'TacoCat';
// const string = 'Cat';

function balancedString(string) {

    let characters = string;
    let w = ''
    let balanced_map = {}
    var shortestBalancedFragment = 10000000000000000000000000;

    for(let i = 0; i < characters.length; i++) {
            w = characters[i];
        for(let j = i + 1; j < characters.length; j++) {
             w +=  characters[j];
             if(checkBalance(w)){
                balanced_map[w] = w.length;
                if(shortestBalancedFragment > w.length){
                    shortestBalancedFragment = w.length
                }
             }

        }
    }
console.log(shortestBalancedFragment)
console.log(balanced_map, w)

if(Object.keys(balanced_map).length == 0) {
    //if no balanced fragment
    return -1;
}
else{
    //return shortest balanced fragment 
    return shortestBalancedFragment
}



}

function checkBalance(word){
    //Approach is to split the word into two arrays lowercase and uppercase arrays
    const lowerLetters = [];
    const upperLetters = [];
    console.log(word)
    for (const char of word) {
        if(checkCase(char) == lower){
            lowerLetters.push(char);
        }else{
            upperLetters.push(char);
        }
    }

    //If there are equal number of letters in both the arrays
    //We check if there are equivalent capital and small letters using the javascript includes method.
    if(lowerLetters.length == upperLetters.length){
        console.log(lowerLetters, upperLetters)
        for (const l of lowerLetters){
            if(!(upperLetters.includes(l.toUpperCase()))){
                return false;
            }
            else{
                continue;
            }
        }
        return true;
    }
return false;

}

//This function checks whether the charater is lower or upper case
function checkCase(character){
    if(character == character.toLowerCase()){
        return lower
    }else{
        return upper
    }
}

console.log("Final Answer, shoretst balanced string length: ", balancedString(string))