neetcode-gh · itaim18 · Feb 9, 2025 · Feb 9, 2025
diff --git a/README.md b/README.md
@@ -497,7 +497,7 @@ If you would like to have collaborator permissions on the repo to merge your own
 <sub>Problem</sub> | <sub>articles</sub> | <sub>C</sub> | <sub>C++</sub> | <sub>C#</sub> | <sub>Dart</sub> | <sub>GO</sub> | <sub>hints</sub> | <sub>Java</sub> | <sub>JS</sub> | <sub>Kotlin</sub> | <sub>Python</sub> | <sub>Ruby</sub> | <sub>Rust</sub> | <sub>Scala</sub> | <sub>Swift</sub> | <sub>TS</sub>
 ---- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | ----
 <sub>[0168 - Excel Sheet Column Title](https://leetcode.com/problems/excel-sheet-column-title/)</sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>[✔️](csharp%2F0168-excel-sheet-column-title.cs)</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>[✔️](java%2F0168-excel-sheet-column-title.java)</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>[✔️](kotlin%2F0168-excel-sheet-column-title.kt)</div></sub> | <sub><div align='center'>[✔️](python%2F0168-excel-sheet-column-title.py)</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub>
-<sub>[1071 - Greatest Common Divisor of Strings](https://leetcode.com/problems/greatest-common-divisor-of-strings/)</sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>[✔️](cpp%2F1071-greatest-common-divisor-of-strings.cpp)</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>[✔️](go%2F1071-greatest-common-divisor-of-strings.go)</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>[✔️](java%2F1071-greatest-common-divisor-of-strings.java)</div></sub> | <sub><div align='center'>[✔️](javascript%2F1071-greatest-common-divisor-of-strings.js)</div></sub> | <sub><div align='center'>[✔️](kotlin%2F1071-greatest-common-divisor-of-strings.kt)</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>[✔️](rust%2F1071-greatest-common-divisor-of-strings.rs)</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>[✔️](typescript%2F1071-greatest-common-divisor-of-strings.ts)</div></sub>
+<sub>[1071 - Greatest Common Divisor of Strings](https://leetcode.com/problems/greatest-common-divisor-of-strings/)</sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>[✔️](cpp%2F1071-greatest-common-divisor-of-strings.cpp)</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>[✔️](go%2F1071-greatest-common-divisor-of-strings.go)</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>[✔️](java%2F1071-greatest-common-divisor-of-strings.java)</div></sub> | <sub><div align='center'>[✔️](javascript%2F1071-greatest-common-divisor-of-strings.js)</div></sub> | <sub><div align='center'>[✔️](kotlin%2F1071-greatest-common-divisor-of-strings.kt)</div></sub> | <sub><div align='center'>[✔️](python%2F1071-greatest-common-divisor-of-strings.py)</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>[✔️](rust%2F1071-greatest-common-divisor-of-strings.rs)</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>[✔️](typescript%2F1071-greatest-common-divisor-of-strings.ts)</div></sub>
 <sub>[1523 - Count Odd Numbers in an Interval Range](https://leetcode.com/problems/count-odd-numbers-in-an-interval-range/)</sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>[✔️](kotlin%2F1523-count-odd-numbers-in-an-interval-range.kt)</div></sub> | <sub><div align='center'>[✔️](python%2F1523-count-odd-numbers-in-an-interval-range.py)</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub>
 <sub>[1572 - Matrix Diagonal Sum](https://leetcode.com/problems/matrix-diagonal-sum/)</sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>[✔️](java%2F1572-matrix-diagonal-sum.java)</div></sub> | <sub><div align='center'>[✔️](javascript%2F1572-matrix-diagonal-sum.js)</div></sub> | <sub><div align='center'>[✔️](kotlin%2F1572-matrix-diagonal-sum.kt)</div></sub> | <sub><div align='center'>[✔️](python%2F1572-matrix-diagonal-sum.py)</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub>
 <sub>[0149 - Maximum Points on a Line](https://leetcode.com/problems/max-points-on-a-line/)</sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>[✔️](cpp%2F0149-max-points-on-a-line.cpp)</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>[✔️](java%2F0149-max-points-on-a-line.java)</div></sub> | <sub><div align='center'>[✔️](javascript%2F0149-max-points-on-a-line.js)</div></sub> | <sub><div align='center'>[✔️](kotlin%2F0149-max-points-on-a-line.kt)</div></sub> | <sub><div align='center'>[✔️](python%2F0149-max-points-on-a-line.py)</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>[✔️](rust%2F0149-max-points-on-a-line.rs)</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>❌</div></sub> | <sub><div align='center'>[✔️](typescript%2F0149-max-points-on-a-line.ts)</div></sub>

diff --git a/kotlin/1143-longest-common-subsequence.kt b/kotlin/1143-longest-common-subsequence.kt
@@ -20,79 +20,4 @@ class Solution {
 		}
 		return dp[M][N]
 	}
-}
-
-/*
- * Different solutions
- */
-
- // Recursion + Memoization, Time Complexity of O(n * m) and space complexity of O(n * m)
-class Solution {
-    fun longestCommonSubsequence(t1: String, t2: String): Int {
-        val n = t1.length
-        val m = t2.length
-        val dp = Array (n) { IntArray (m) { -1 } }
-
-        fun dfs(i: Int, j: Int): Int {
-            if (i == n || j == m) return 0
-            if (dp[i][j] != -1) return dp[i][j]
-
-            if (t1[i] == t2[j])
-                dp[i][j] = 1 + dfs(i + 1, j + 1)
-            else
-                dp[i][j] = maxOf(dfs(i + 1, j), dfs(i, j + 1))
-
-            return dp[i][j]
-        }
-
-        return dfs(0, 0)
-    }
-}
-
-// Top down DP, Time Complexity of O(n * m) and space complexity of O(n * m)
-class Solution {
-    fun longestCommonSubsequence(t1: String, t2: String): Int {
-        val n = t1.length
-        val m = t2.length
-        val dp = Array (n + 1) { IntArray (m + 1) }
-
-        for (i in n - 1 downTo 0) {
-            for (j in m - 1 downTo 0) {
-                if (t1[i] == t2[j])
-                    dp[i][j] = 1 + dp[i + 1][j + 1]
-                else
-                    dp[i][j] = maxOf(dp[i + 1][j], dp[i][j + 1])
-            }
-        }
-
-        return dp[0][0]
-    }
-}
-
-// Optimized DP (Works both for both Top-down and Bottom-up, but here we use bottom-up approach)
-// Time Complexity of O(n * m) and space complexity of O(maxOf(n, m))
-class Solution {
-    fun longestCommonSubsequence(t1: String, t2: String): Int {
-        val m = t1.length
-        val n = t2.length
-        if (m < n) return longestCommonSubsequence(t2, t1)
-
-        var dp = IntArray (n + 1)
-
-        for (i in m downTo 0) {
-            var newDp = IntArray (n + 1)
-            for (j in n downTo 0) {
-                if (i == m || j == n) {
-                    newDp[j] = 0
-                } else if (t1[i] == t2[j]) {
-                    newDp[j] = 1 + dp[j + 1]
-                } else {
-                    newDp[j] = maxOf(dp[j], newDp[j + 1])
-                }
-            }
-            dp = newDp
-        }
-
-        return dp[0]
-    }
-}
+}
diff --git a/python/1071-greatest-common-divisor-of-strings.py b/python/1071-greatest-common-divisor-of-strings.py
@@ -0,0 +1,15 @@
+class Solution:
+    def gcdOfStrings(self, str1: str, str2: str) -> str:
+        len1, len2 = len(str1), len(str2)
+
+        def valid(k):
+            if len1 % k or len2 % k: 
+                return False
+            n1, n2 = len1 // k, len2 // k
+            base = str1[:k]
+            return str1 == n1 * base and str2 == n2 * base 
+
+        for i in range(min(len1, len2), 0, -1):
+            if valid(i):
+                return str1[:i]
+        return ""