String -- Leetcode ♥ Welcome to Ting's Castle =)

Reverse String QuestionEditorial Solution My Submissions Total Accepted: 72892 Total Submissions: 124678 Difficulty: Easy Write a function that takes a string as input and returns the string reversed.

Example: Given s = “hello”, return “olleh”.

// Basic run time: 100ms
var reverseString = function(s) {
    var arr = s.split(""),
        len = arr.length,
        result = '';

    for (var i = arr.length - 1; i >= 0; i--) {
      result += arr[i];
    }

    return result;
};

console.log(reverseString('hello'));	

// run time: 104ms
var reverseString = function(s) {
    var result = "";
  
    for(var i=s.length-1; i>=0; i--) {
      result += s[i];
    }
  
    return result;
};

console.log(reverseString("hello"));
	
// run time: 88ms
var reverseString = function(s) {
var arr = s.split(""),
    len = arr.length;

for (var i = 0, max = (len - 1) / 2; i < max; i++) {
  var temp = arr[i];
      arr[i] = arr[len - 1 - i];
      arr[len - 1 - i] = temp;
}

return arr.join("");
};

console.log(reverseString('hello'));

Valid Anagram QuestionEditorial Solution My Submissions Total Accepted: 102563 Total Submissions: 236093 Difficulty: Easy Given two strings s and t, write a function to determine if t is an anagram of s.

For example, s = “anagram”, t = “nagaram”, return true. s = “rat”, t = “car”, return false.

Note: You may assume the string contains only lowercase alphabets.

Follow up: What if the inputs contain unicode characters? How would you adapt your solution to such case?

// run time: 96ms
var isAnagram = function(s, t) {
    
    if (s.length !== t.length) {
      return false;
    }

    var str1 = s.split("").sort().join("");
    var str2 = t.split("").sort().join("");

    return str1 === str2;
};

console.log(isAnagram("anagrah", "nagaram"));

Word Pattern

Given a pattern and a string str, find if str follows the same pattern.

Here follow means a full match, such that there is a bijection between a letter in pattern and a non-empty word in str.

Examples: pattern = “abba”, str = “dog cat cat dog” should return true. pattern = “abba”, str = “dog cat cat fish” should return false. pattern = “aaaa”, str = “dog cat cat dog” should return false. pattern = “abba”, str = “dog dog dog dog” should return false. Notes: You may assume pattern contains only lowercase letters, and str contains lowercase letters separated by a single space.

Compare Version Numbers

/**
 * @param {string} version1
 * @param {string} version2
 * @return {number}
 */
var compareVersion = function(version1, version2) {
    var s1 = version1.toString(),
        s2 = version2.toString();
  
    var num1 = parseInt(s1.slice(0, s1.indexOf('.'))),
        num2 = parseInt(s2.slice(0, s2.indexOf('.')));
  
    if(num1 > num2 ) return 1;
  
    if(num1 < num2) return -1;
  
    if(num1 == num2) {
      var pose1 = parseInt(s1.slice(s1.indexOf('.') + 1)),
          pose2 = parseInt(s2.slice(s2.indexOf('.') + 1));
      
      if(pose1 > pose2) {
        return 1;
      } else if (pose1 < pose2) {
        return -1;
      } else {
        return 0;
      }
    }
                        
};

console.log(compareVersion(2.1, 1.1));

ZigZag Conversion
Implement strStr()