Add solution #576

Author: JoshCrozier

README.md

@@ -452,6 +452,7 @@
 567|[Permutation in String](./0567-permutation-in-string.js)|Medium|
 572|[Subtree of Another Tree](./0572-subtree-of-another-tree.js)|Easy|
 575|[Distribute Candies](./0575-distribute-candies.js)|Easy|
+576|[Out of Boundary Paths](./0576-out-of-boundary-paths.js)|Medium|
 589|[N-ary Tree Preorder Traversal](./0589-n-ary-tree-preorder-traversal.js)|Easy|
 594|[Longest Harmonious Subsequence](./0594-longest-harmonious-subsequence.js)|Easy|
 599|[Minimum Index Sum of Two Lists](./0599-minimum-index-sum-of-two-lists.js)|Easy|

solutions/0576-out-of-boundary-paths.js

@@ -0,0 +1,44 @@
+/**
+ * 576. Out of Boundary Paths
+ * https://leetcode.com/problems/out-of-boundary-paths/
+ * Difficulty: Medium
+ *
+ * There is an m x n grid with a ball. The ball is initially at the position [startRow,
+ * startColumn]. You are allowed to move the ball to one of the four adjacent cells in
+ * the grid (possibly out of the grid crossing the grid boundary). You can apply at most
+ * maxMove moves to the ball.
+ *
+ * Given the five integers m, n, maxMove, startRow, startColumn, return the number of
+ * paths to move the ball out of the grid boundary. Since the answer can be very large,
+ * return it modulo 109 + 7.
+ */
+
+/**
+ * @param {number} m
+ * @param {number} n
+ * @param {number} maxMove
+ * @param {number} startRow
+ * @param {number} startColumn
+ * @return {number}
+ */
+var findPaths = function(m, n, maxMove, startRow, startColumn) {
+  const MOD = 1e9 + 7;
+  const directions = [[0, 1], [0, -1], [1, 0], [-1, 0]];
+  const dp = new Array(maxMove + 1).fill().map(() => {
+    return new Array(m).fill().map(() => new Array(n).fill(-1));
+  });
+
+  return solve(maxMove, startRow, startColumn);
+
+  function solve(moves, row, col) {
+    if (row < 0 || row >= m || col < 0 || col >= n) return 1;
+    if (moves === 0) return 0;
+    if (dp[moves][row][col] !== -1) return dp[moves][row][col];
+
+    let paths = 0;
+    for (const [dr, dc] of directions) {
+      paths = (paths + solve(moves - 1, row + dr, col + dc)) % MOD;
+    }
+    return dp[moves][row][col] = paths;
+  }
+};