Add solution #546

Author: JoshCrozier

README.md

@@ -434,6 +434,7 @@
 541|[Reverse String II](./0541-reverse-string-ii.js)|Easy|
 542|[01 Matrix](./0542-01-matrix.js)|Medium|
 543|[Diameter of Binary Tree](./0543-diameter-of-binary-tree.js)|Easy|
+546|[Remove Boxes](./0546-remove-boxes.js)|Hard|
 547|[Number of Provinces](./0547-number-of-provinces.js)|Medium|
 551|[Student Attendance Record I](./0551-student-attendance-record-i.js)|Easy|
 557|[Reverse Words in a String III](./0557-reverse-words-in-a-string-iii.js)|Easy|

solutions/0546-remove-boxes.js

@@ -0,0 +1,42 @@
+/**
+ * 546. Remove Boxes
+ * https://leetcode.com/problems/remove-boxes/
+ * Difficulty: Hard
+ *
+ * You are given several boxes with different colors represented by different positive numbers.
+ *
+ * You may experience several rounds to remove boxes until there is no box left. Each time you
+ * can choose some continuous boxes with the same color (i.e., composed of k boxes, k >= 1),
+ * remove them and get k * k points.
+ *
+ * Return the maximum points you can get.
+ */
+
+/**
+ * @param {number[]} boxes
+ * @return {number}
+ */
+var removeBoxes = function(boxes) {
+  const dp = new Array(boxes.length).fill().map(() => {
+    return new Array(boxes.length).fill().map(() => new Array(boxes.length + 1).fill(0));
+  });
+  return dfs(0, boxes.length - 1, 0);
+
+  function dfs(l, r, k) {
+    if (l > r) return 0;
+    if (dp[l][r][k]) return dp[l][r][k];
+    let i = l;
+    let count = k + 1;
+    while (i < r && boxes[i] === boxes[i + 1]) {
+      i++;
+      count++;
+    }
+    let max = count * count + dfs(i + 1, r, 0);
+    for (let m = i + 1; m <= r; m++) {
+      if (boxes[l] === boxes[m]) {
+        max = Math.max(max, dfs(i + 1, m - 1, 0) + dfs(m, r, count));
+      }
+    }
+    return dp[l][r][k] = max;
+  }
+};