From b7c8081053e9e87a26c50ebe10b0d1b1427676d6 Mon Sep 17 00:00:00 2001
From: Rostislav Kuratch <kr0st@bioreactor.me>
Date: Thu, 16 Jun 2022 23:08:56 +0300
Subject: [PATCH] "3. Longest Substring Without Repeating Characters"
 drastically optimised accepted solution

---
 3-longest-substr-no-repeat-chars.go | 33 +++++++++++++++++++++++++++--
 1 file changed, 31 insertions(+), 2 deletions(-)

diff --git a/3-longest-substr-no-repeat-chars.go b/3-longest-substr-no-repeat-chars.go
index aaf6b82..e33351a 100644
--- a/3-longest-substr-no-repeat-chars.go
+++ b/3-longest-substr-no-repeat-chars.go
@@ -86,6 +86,35 @@ func lengthOfLongestSubstringSlidingWindow(s string) int {
 	return maxChars
 }
 
-func LengthOfLongestSubstring(s string) int {
-	return lengthOfLongestSubstringSlidingWindow(s)
+func lengthOfLongestSubstringExpandingWindow(s string) int {
+	maxChars := 0
+
+	if len(s) == 0 {
+		return 0
+	}
+
+	for i := 0; i < len(s)-maxChars; i++ {
+		charMap := [255]int{}
+		charMapSize := 0
+
+		for j := i; j < len(s); j++ {
+			charMap[s[j]]++
+			if charMap[s[j]] > 1 {
+				break
+			} else {
+				charMapSize++
+			}
+
+		}
+
+		if maxChars < charMapSize {
+			maxChars = charMapSize
+		}
+	}
+
+	return maxChars
+}
+
+func LengthOfLongestSubstring(s string) int {
+	return lengthOfLongestSubstringExpandingWindow(s)
 }