feat(work): add new Easy difficulty problems for Hash Table and Two Pointers modules

work/Easy/Hash Table/1832.check-if-the-sentence-is-pangram.js

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+/*
+ * 1832. Check if the Sentence Is Pangram
+ * Difficulty: Easy
+ * https://leetcode.com/problems/check-if-the-sentence-is-pangram/
+ * 
+ * ──────────────────────────────────────────────────
+ * 
+ * A pangram is a sentence where every letter of the English alphabet
+ * appears at least once.
+ * 
+ * Given a string sentence containing only lowercase English letters,
+ * return true if sentence is a pangram, or false otherwise.
+ * 
+ *  
+ * 
+ * Example 1:
+ * 
+ * Input: sentence = "thequickbrownfoxjumpsoverthelazydog"
+ * Output: true
+ * Explanation: sentence contains at least one of every letter of the
+ * English alphabet.
+ * 
+ * Example 2:
+ * 
+ * Input: sentence = "leetcode"
+ * Output: false
+ * 
+ *  
+ * 
+ * Constraints:
+ * 
+ * 	• 1 <= sentence.length <= 1000
+ * 
+ * 	• sentence consists of lowercase English letters.
+*/
+
+/**
+ * @param {string} sentence
+ * @return {boolean}
+ */
+var checkIfPangram = function(sentence) {
+    const freq = {};
+    for (let c of sentence) freq[c] = (freq[c] || 0) + 1;
+    
+    if (Object.keys(freq).length === 26){
+        return true;
+    }
+    return false;
+};

work/Easy/Two Pointers/344.reverse-string.js

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+/*
+ * 344. Reverse String
+ * Difficulty: Easy
+ * https://leetcode.com/problems/reverse-string/
+ * 
+ * ──────────────────────────────────────────────────
+ * 
+ * Write a function that reverses a string. The input string is given as
+ * an array of characters s.
+ * 
+ * You must do this by modifying the input array in-place with O(1)
+ * extra memory.
+ * 
+ *  
+ * 
+ * Example 1:
+ * 
+ * Input: s = ["h","e","l","l","o"]
+ * Output: ["o","l","l","e","h"]
+ * 
+ * Example 2:
+ * 
+ * Input: s = ["H","a","n","n","a","h"]
+ * Output: ["h","a","n","n","a","H"]
+ * 
+ *  
+ * 
+ * Constraints:
+ * 
+ * 	• 1 <= s.length <= 10^5
+ * 
+ * 	• s[i] is a printable ascii character.
+*/
+
+/**
+ * @param {character[]} s
+ * @return {void} Do not return anything, modify s in-place instead.
+ */
+var reverseString = function(s) {
+
+    let i = 0;
+    let j = s.length - 1;
+    
+    while (i < j) {
+        [s[i], s[j]] = [s[j], s[i]];
+        j--;
+        i++;
+    }
+};