Add solution #490

JoshCrozier · JoshCrozier · commit 0d044daa06b6 · 2025-06-18T23:35:31.000-05:00
diff --git a/README.md b/README.md
@@ -478,6 +478,7 @@
 487|[Max Consecutive Ones II](./solutions/0487-max-consecutive-ones-ii.js)|Medium|
 488|[Zuma Game](./solutions/0488-zuma-game.js)|Hard|
 489|[Robot Room Cleaner](./solutions/0489-robot-room-cleaner.js)|Hard|
+490|[The Maze](./solutions/0490-the-maze.js)|Medium|
 491|[Non-decreasing Subsequences](./solutions/0491-non-decreasing-subsequences.js)|Medium|
 492|[Construct the Rectangle](./solutions/0492-construct-the-rectangle.js)|Easy|
 493|[Reverse Pairs](./solutions/0493-reverse-pairs.js)|Hard|
diff --git a/solutions/0490-the-maze.js b/solutions/0490-the-maze.js
@@ -0,0 +1,52 @@
+/**
+ * 490. The Maze
+ * https://leetcode.com/problems/the-maze/
+ * Difficulty: Medium
+ *
+ * There is a ball in a maze with empty spaces (represented as 0) and walls (represented as 1).
+ * The ball can go through the empty spaces by rolling up, down, left or right, but it won't
+ * stop rolling until hitting a wall. When the ball stops, it could choose the next direction.
+ *
+ * Given the m x n maze, the ball's start position and the destination, where
+ * start = [startrow, startcol] and destination = [destinationrow, destinationcol],
+ * return true if the ball can stop at the destination, otherwise return false.
+ *
+ * You may assume that the borders of the maze are all walls (see examples).
+ */
+
+/**
+ * @param {number[][]} maze
+ * @param {number[]} start
+ * @param {number[]} destination
+ * @return {boolean}
+ */
+var hasPath = function(maze, start, destination) {
+  const rows = maze.length;
+  const cols = maze[0].length;
+  const visited = new Set();
+  const directions = [[-1, 0], [1, 0], [0, -1], [0, 1]];
+
+  return helper(start[0], start[1]);
+
+  function helper(row, col) {
+    if (visited.has(`${row},${col}`)) return false;
+    visited.add(`${row},${col}`);
+
+    if (row === destination[0] && col === destination[1]) return true;
+
+    for (const [dr, dc] of directions) {
+      let newRow = row;
+      let newCol = col;
+
+      while (newRow + dr >= 0 && newRow + dr < rows && newCol + dc >= 0 && newCol + dc < cols
+             && maze[newRow + dr][newCol + dc] === 0) {
+        newRow += dr;
+        newCol += dc;
+      }
+
+      if (helper(newRow, newCol)) return true;
+    }
+
+    return false;
+  }
+};
