Merge pull request neetcode-gh#769 from kciccolella/leetcode329

Create 329-Longest-Increasing-Path-in-a-Matrix.js

Author: Ahmad-A0

javascript/329-Longest-Increasing-Path-in-a-Matrix.js

@@ -0,0 +1,37 @@
+/**
+ * @param {number[][]} matrix
+ * @return {number}
+ */
+var longestIncreasingPath = function(matrix) {
+    const ROWS = matrix.length;
+    const COLS = matrix[0].length;
+    const dp = {}; // r|c -> LIP
+    
+    function dfs(r, c, prevVal) {
+        if (r < 0 || r === ROWS ||
+            c < 0 || c === COLS ||
+            matrix[r][c] <= prevVal) {
+            return 0;
+        }
+        
+        if (dp.hasOwnProperty(`${r}|${c}`)) {
+            return dp[`${r}|${c}`];
+        }
+        
+        let res = 1;
+        res = Math.max(res, 1 + dfs(r + 1, c, matrix[r][c]));
+        res = Math.max(res, 1 + dfs(r - 1, c, matrix[r][c]));
+        res = Math.max(res, 1 + dfs(r, c + 1, matrix[r][c]));
+        res = Math.max(res, 1 + dfs(r, c - 1, matrix[r][c]));
+        dp[`${r}|${c}`] = res;
+        return res;
+    }
+    
+    for (var r = 0; r < ROWS; r++) {
+        for (var c = 0; c < COLS; c++) {
+            dfs(r, c, -1);
+        }
+    }
+    
+    return Math.max(...Object.values(dp));
+}