feat: 659.encode-and-decode-strings

Author: gwbaik9717

encode-and-decode-strings/gwbaik9717.js

@@ -0,0 +1,37 @@
+// n: len(str)
+// Time complexity: O(n)
+// Space complexity: O(1)
+const encode = function (arr) {
+  let answer = "";
+
+  for (const word of arr) {
+    answer += `${word.length}${SEPERATOR}`;
+  }
+
+  return answer;
+};
+
+// n: len(str)
+// Time complexity: O(n)
+// Space complexity: O(n)
+const decode = function (str) {
+  const SEPERATOR = "|";
+  const words = [];
+
+  let i = 0;
+  let wordLength = "";
+
+  while (i < str.length) {
+    if (str[i] === SEPERATOR) {
+      words.push(str.slice(i + 1, i + 1 + Number(wordLength)));
+      i += Number(wordLength) + 1;
+      wordLength = "";
+      continue;
+    }
+
+    wordLength += str[i];
+    i += 1;
+  }
+
+  return words;
+};