java: add “2684. Maximum Number of Moves in a Grid”

Signed-off-by: Matej Focko <me@mfocko.xyz>

java/maximum-number-of-moves-in-a-grid.java

@@ -0,0 +1,27 @@
+class Solution {
+    public int maxMoves(int[][] grid) {
+        int[][] dp = new int[grid.length][grid[0].length];
+
+        for (int x = grid[0].length - 2; x >= 0; --x) {
+            for (int y = 0; y < dp.length; ++y) {
+                // check neighbours for moves
+                for (int dy = -1; dy <= 1; ++dy) {
+                    int ny = y + dy;
+                    if (ny < 0 || ny >= dp.length || grid[y][x] >= grid[ny][x + 1]) {
+                        continue;
+                    }
+
+                    dp[y][x] = Math.max(dp[y][x], 1 + dp[ny][x + 1]);
+                }
+            }
+        }
+
+        int m = 0;
+        for (int y = 0; y < grid.length; ++y) {
+            m = Math.max(m, dp[y][0]);
+        }
+
+        return m;
+    }
+}
+