JS 면접 알고리즘 문제 (1)

function palindromeString(str) {
    return str === str.split('').reverse().join('');
}

function removeRepeat(arr) {
    var hash = {};
    var data = [];
    for(var i = 0; i < arr.length; i++) {
        if(!hash[arr[i]]) {
            hash[arr[i]] = true;
            data.push(arr[i]);
        }
    }
    return data;
}

function removeRepeat(arr) {
    return Array.from(new Set(arr));
}

function findMaxChar(str) {
    if(str.length === 1) {
        return str;
    }
    var charObj = {};
    for(var i = 0; i < str.length; i++) {
        if(!charObj[str[i]]) {
            charObj[str[i]] = 1;
        } else {
            charObj[str[i]] += 1;
        }
    }
    var char = '';
    var maxValue = 0;
    for(var k in charObj) {
        if(charObj[k] >= maxValue) {
            char = k;
            maxValue = charObj[k];
        }
    }
    return char;
}

function swap(a, b) {
    b = b - a;
    a = a + b;
    b = a - b;
    return [a, b];
}

function getMax(arr) {
    var min = arr[0], max = 0;
    for(var i = 0; i < arr.length; i++) {
        min = Math.min(min, arr[i]);
        max = Math.max(max, arr[i]);
    }
    return max - min;
}

function randomStr(n) {
            var str = 'abcdefghijklmnopqrstuvwxyz9876543210';
            var temp = '';
            var len = str.length;
            for(var i = 0; i < n; ++i) {
                temp += str.charAt(Math.floor(Math.random() * len));
            }
            return temp;
        }