✨ [q3] First approach, havent submitted

Author: enkr1

3/solution.js

@@ -0,0 +1,41 @@
+/**
+ * @param {string} s
+ * @return {number}
+ */
+const lengthOfLongestSubstring = (s) => {
+  // Put into a map {index: 0, char: "a", nbAppeared: 1}
+  let tmpMap = new Map(),
+    charList = s.split(''),
+    tmpResult = [], // Deciding result
+    result = [];
+
+  for (let i = 0; i < charList.length; i++) {
+    // Might need extra handle if there is upper/lower case.
+    let currChar = charList[i],
+      existCharMap = tmpMap.get(currChar);
+
+    if (existCharMap) {
+      tmpResult = [currChar]; // Reset the tmp result
+
+      // Update values
+      existCharMap.nbAppeared += 1;
+      tmpMap.set(currChar, existCharMap);
+    } else {
+      // Set it into the map if doesnt exists
+      tmpMap.set(currChar, { index: i, nbAppeared: 1 })
+      tmpResult.push(currChar)
+    }
+
+    if (tmpResult.length > result.length) result = tmpResult;
+  }
+
+
+  console.log("final output:")
+  console.log(tmpMap)
+  console.log(result.join(""))
+  return result.join("");
+};
+
+// lengthOfLongestSubstring("abcabcbb") // abc
+// lengthOfLongestSubstring("bbbbb") // b
+// lengthOfLongestSubstring("pwwkew") // wke