[Algorithm] 22 week(6.13 ~ 6.19) 2/3

242. Valid Anagram

var isAnagram = function(s, t) {
    if (s.length !== t.length) return false;
    
    const map = {};
    
    for (let i = 0; i < s.length; i++) {
        if (map[s[i]]) {
            map[s[i]] = ++map[s[i]];
        }       
        else {
            map[s[i]] = 1;
        }
    }

    for (let i = 0; i < t.length; i++) {
        if (!map[t[i]]) return false;
        map[t[i]] = --map[t[i]];
    }
    
    return true;
};