solved: 3

Author: ryoppippi

code/3.longest-substring-without-repeating-characters.ts

@@ -0,0 +1,21 @@
+function lengthOfLongestSubstring(str: string): number {
+  let ans = 0;
+
+  let pos = -1;
+
+  const map = new Map<string, number>();
+
+  Array.from(str).forEach((char, index) => {
+    const d = map.get(char);
+
+    /** if map has char previous index and the candidate left position is less than the previous index, update the left position */
+    if (d != null && d > pos) {
+      pos = d;
+    }
+
+    map.set(char, index);
+
+    ans = Math.max(ans, index - pos);
+  });
+  return ans;
+}