Longest Substring Without Repeating Characters

Author: TonyKim9401

longest-substring-without-repeating-characters/TonyKim9401.java

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+// TC: O(n^2)
+// -> all elements can be retrived multiple times in the worst case
+// SC: O(1)
+// -> since declare, no more increase or decrease
+class Solution {
+    public int lengthOfLongestSubstring(String s) {
+        int max = 0;
+        int count = 0;
+        boolean[] checkList = new boolean[128];
+
+        for (int i = 0; i < s.length(); i++) {
+            int idx = s.charAt(i);
+            if (checkList[idx]) {
+                max = Math.max(max, count);
+                i -= count;
+                count = 0;
+                checkList = new boolean[128];
+            } else {
+                count += 1;
+                checkList[idx] = true;
+            }
+        }
+        return max = Math.max(max, count);
+    }
+}