Add solution to 3459

Author: absurdusername

solution/3400-3499/3459.Length of Longest V-Shaped Diagonal Segment/README.md

@@ -119,7 +119,40 @@ tags:
 #### Python3
 
 ```python
+class Solution:
+    def lenOfVDiagonal(self, grid: List[List[int]]) -> int:
+        m, n = len(grid), len(grid[0])
+        next_digit = {1: 2, 2: 0, 0: 2}
 
+        def within_bounds(i, j):
+            return 0 <= i < m and 0 <= j < n
+
+        @cache
+        def f(i, j, di, dj, turned):
+            result = 1
+            successor = next_digit[grid[i][j]]
+
+            if within_bounds(i + di, j + dj) and grid[i + di][j + dj] == successor:
+                result = 1 + f(i + di, j + dj, di, dj, turned)
+
+            if not turned:
+                di, dj = dj, -di
+                if within_bounds(i + di, j + dj) and grid[i + di][j + dj] == successor:
+                    result = max(result, 1 + f(i + di, j + dj, di, dj, True))
+
+            return result
+
+        directions = ((1, 1), (-1, 1), (1, -1), (-1, -1))
+        result = 0
+
+        for i in range(m):
+            for j in range(n):
+                if grid[i][j] != 1:
+                    continue
+                for di, dj in directions:
+                    result = max(result, f(i, j, di, dj, False))
+
+        return result
 ```
 
 #### Java

solution/3400-3499/3459.Length of Longest V-Shaped Diagonal Segment/README_EN.md

@@ -117,7 +117,40 @@ tags:
 #### Python3
 
 ```python
+class Solution:
+    def lenOfVDiagonal(self, grid: List[List[int]]) -> int:
+        m, n = len(grid), len(grid[0])
+        next_digit = {1: 2, 2: 0, 0: 2}
 
+        def within_bounds(i, j):
+            return 0 <= i < m and 0 <= j < n
+
+        @cache
+        def f(i, j, di, dj, turned):
+            result = 1
+            successor = next_digit[grid[i][j]]
+
+            if within_bounds(i + di, j + dj) and grid[i + di][j + dj] == successor:
+                result = 1 + f(i + di, j + dj, di, dj, turned)
+
+            if not turned:
+                di, dj = dj, -di
+                if within_bounds(i + di, j + dj) and grid[i + di][j + dj] == successor:
+                    result = max(result, 1 + f(i + di, j + dj, di, dj, True))
+
+            return result
+
+        directions = ((1, 1), (-1, 1), (1, -1), (-1, -1))
+        result = 0
+
+        for i in range(m):
+            for j in range(n):
+                if grid[i][j] != 1:
+                    continue
+                for di, dj in directions:
+                    result = max(result, f(i, j, di, dj, False))
+
+        return result
 ```
 
 #### Java

solution/3400-3499/3459.Length of Longest V-Shaped Diagonal Segment/Solution.py

@@ -0,0 +1,34 @@
+class Solution:
+    def lenOfVDiagonal(self, grid: List[List[int]]) -> int:
+        m, n = len(grid), len(grid[0])
+        next_digit = {1: 2, 2: 0, 0: 2}
+
+        def within_bounds(i, j):
+            return 0 <= i < m and 0 <= j < n
+
+        @cache
+        def f(i, j, di, dj, turned):
+            result = 1
+            successor = next_digit[grid[i][j]]
+
+            if within_bounds(i + di, j + dj) and grid[i + di][j + dj] == successor:
+                result = 1 + f(i + di, j + dj, di, dj, turned)
+
+            if not turned:
+                di, dj = dj, -di
+                if within_bounds(i + di, j + dj) and grid[i + di][j + dj] == successor:
+                    result = max(result, 1 + f(i + di, j + dj, di, dj, True))
+
+            return result
+
+        directions = ((1, 1), (-1, 1), (1, -1), (-1, -1))
+        result = 0
+
+        for i in range(m):
+            for j in range(n):
+                if grid[i][j] != 1:
+                    continue
+                for di, dj in directions:
+                    result = max(result, f(i, j, di, dj, False))
+
+        return result