Encode and Decode Strings solution

Author: kim-young

encode-and-decode-strings/kimyoung.js

@@ -0,0 +1,47 @@
+/**
+ * Encodes a list of strings to a single string.
+ *
+ * @param {string[]} strs
+ * @return {string}
+ */
+
+const DELIMITER = "#";
+
+var encode = function (strs) {
+  let temp = "";
+  for (const str of strs) { // encode using the delimiter by attaching the length of the array as well
+    temp += `${str.length}${DELIMITER}` + str; 
+  }
+  return temp;
+};
+
+/**
+ * Decodes a single string to a list of strings.
+ *
+ * @param {string} s
+ * @return {string[]}
+ */
+var decode = function (s) { // decode using the length of array that is attached with the delimiter
+  let result = [];
+  let i = 0;
+  while (i < s.length) {
+    let j = i;
+    while (s[j] !== DELIMITER) j++;
+    const len = Number(s.slice(i, j));
+    const word = s.slice(j + 1, j + len + 1);
+    result.push(word);
+    i = j + len + 1;
+  }
+  return result;
+};
+
+/**
+ * Your functions will be called as such:
+ * decode(encode(strs));
+ */
+
+// test cases
+console.log(["Hello", "World"]);
+
+// time - O(n) - iterate through the list of strings once
+// space - O(n) - stores the strings