Coding Challenge #16 Distance to nearest vowel

 Distance to nearest Vowel (Edabit)
Given a string, return an array with the distance to the nearest vowel for each character. It searches for the nearest both forwards and backwards.

Example: 'abc' -> [0,1,2]

'abzxciou' -> [0,1,1,2,2,0,0,0]

We'll force lowercase and make non-letter characters return "N/A" in the array.

function doit(str){
    var o = [];
    str = str.toLowerCase();
    
    for(var xint = 0, len = str.length;xint < len;xint++){
        var c = str.charCodeAt(xint);
        if(c >= aCode && c <= zCode){ // is a letter
            // we'll just manually check by looping. use modulo to contain value.
            var leastVowelDistance = 26;
            var forwardsVowelDistance = 26;
            var backwardsVowelDistance = 26;
            var cOffset = c - aCode;
            for(var yint=0;yint<25;yint++){ // forward
                var xchar = alphabet[(cOffset + yint) % 26]; // for upward
                if(xchar == 'a' || xchar == 'e' || xchar == 'i' || xchar == 'o' || xchar == 'u'){
                    forwardsVowelDistance = yint;
                    break;
                }
            }
           
            for(var yint = 0;yint < 25;yint++){ // backwards
                var xidx = cOffset - yint + (yint > cOffset ? 26 : 0);
                var xchar = alphabet[xidx];
               
                if(xchar == 'a' || xchar == 'e' || xchar == 'i' || xchar == 'o' || xchar == 'u'){
                    backwardsVowelDistance = yint;
                    break;
                }
            }
           
            leastVowelDistance = Math.min(forwardsVowelDistance,backwardsVowelDistance);
            o.push(leastVowelDistance);
           
            // debug info, shows the distance forwards and backwards for each letter
            //console.log("Letter = " + alphabet[cOffset] + ", forwardsVowelDistance = " + forwardsVowelDistance + ", backwardsVowelDistance = " + backwardsVowelDistance + ", leastVowelDistance = " + leastVowelDistance);
        }else{
            o.push('N/A'); // not a letter
        }
    }
    
    return o;
}
// note: we're not using 'y' as a vowel here
var vowels = ['a'.charCodeAt(0),'e'.charCodeAt(0),'i'.charCodeAt(0),'o'.charCodeAt(0),'u'.charCodeAt(0)];
var alphabet = [];
var aCode = 'a'.charCodeAt(0);
var zCode = 'z'.charCodeAt(0);
for(var xint=0;xint<26;xint++)alphabet.push(String.fromCharCode(aCode+xint));
function test(str){
    if(str == undefined){ // make random string
        var len = 5;
        str = "";
        var range = zCode - aCode;
        for(var xint = 0;xint < len;xint++)
            str += String.fromCharCode( Math.round(Math.random()*range) + aCode);
    }
    console.log('str: ' + str + '. result: ' + doit(str).toString());
}



test('abc');
test('xyz');
test('cabbage');
test('Spider Man');
test('$ #@ ^*$@ #*');
test('AaAaHhHh');
test('그거양은 체친구입니다.');
for(var xint = 0;xint < 5;xint++) test();