"Longest Duplicate Substring" hard task No 1044 not accepted improved bruteforce solution

1044-longest-duplicate-substring.go

@@ -52,6 +52,47 @@ func LongestDupSubstringReversedBruteforce(s string) string {
 	return ""
 }
 
-func LongestDupSubstring(s string) string {
-	return LongestDupSubstringBruteforce(s)
+func LongestDupSubstringSmartforce(s string) string {
+	strLen := len(s)
+	if strLen < 2 {
+		return ""
+	}
+
+	indicesCurrent := []int{}
+	indicesNext := []int{}
+
+	res := ""
+	for i := 0; i < strLen; i++ {
+
+		for j := 0; j < strLen; j++ {
+			indicesCurrent = append(indicesCurrent, j)
+		}
+
+		for ln := 1; ln <= strLen-i; ln++ {
+			word1 := s[i : i+ln]
+
+			for _, index := range indicesCurrent {
+				if index+ln > strLen {
+					continue
+				}
+				word2 := s[index : index+ln]
+				if (word1 == word2) && (index != i) {
+
+					if len(res) < len(word1) {
+						res = word1
+					}
+					indicesNext = append(indicesNext, index)
+				}
+			}
+
+			indicesCurrent = indicesNext
+			indicesNext = []int{}
+		}
+	}
+
+	return res
+}
+
+func LongestDupSubstring(s string) string {
+	return LongestDupSubstringSmartforce(s)
 }