🔥 Word Search

Author: maddhruv

README.md

@@ -22,3 +22,4 @@ Solutions of LeetCode Blind 75 Problems in JavaScript
 | [Missing Number]()                                                                |                                                           |                                                    | [:link:](https://leetcode.com/problems/missing-number/)                       |
 | [Reverse Bits]()                                                                  |                                                           |                                                    | [:link:](https://leetcode.com/problems/reverse-bits/)                         |
 | [Climbing Stairs](./climbing-stairs.js)                                           | <img src="https://img.shields.io/badge/-Easy-green" />    | `Math`, `Dynamic Programming`, `Memoization`       | [:link:](https://leetcode.com/problems/climbing-stairs/)                      |
+| [Word Search](./word-search.js)                                                   | <img src="https://img.shields.io/badge/-Medium-orange" /> | `Array`, `Backtracking`, `Matrix`                  | [:link:](https://leetcode.com/problems/word-search/)                          |

word-search.js

@@ -0,0 +1,37 @@
+const exist = (board, word) => {
+  const rows = board.length,
+    columns = board[0].length,
+    visited = new Set();
+
+  const dfs = (r, c, index) => {
+    if (index === word.length) return true;
+    if (
+      r < 0 ||
+      c < 0 ||
+      r >= rows ||
+      c >= columns ||
+      board[r][c] !== word[index] ||
+      visited.has(`${r},${c}`)
+    )
+      return false;
+
+    visited.add(`${r},${c}`);
+    let result =
+      dfs(r - 1, c, index + 1) ||
+      dfs(r + 1, c, index + 1) ||
+      dfs(r, c - 1, index + 1) ||
+      dfs(r, c + 1, index + 1);
+    visited.delete(`${r},${c}`);
+    return result;
+  };
+
+  for (let r = 0; r < rows; r++) {
+    for (let c = 0; c < columns; c++) {
+      if (dfs(r, c, 0)) {
+        return true;
+      }
+    }
+  }
+
+  return false;
+};