Merge pull request #3723 from drxlx/0312-burst-balloons

Create 0312-burst-balloons.swift

Author: Ykhan799

swift/0312-burst-balloons.swift

@@ -0,0 +1,26 @@
+class Solution {
+    func maxCoins(_ nums: [Int]) -> Int {
+        var nums = [1] + nums + [1]
+        var dp = [[Int]: Int]()
+
+        func dfs(_ l: Int, _ r: Int) -> Int {
+            if l > r {
+                return 0
+            }
+            if dp[[l, r]] != nil {
+                return dp[[l, r]]!
+            }
+
+            dp[[l, r]] = 0
+            for i in l...r {
+                var coins = nums[l - 1] * nums[i] * nums[r + 1]
+                coins += dfs(l, i - 1) + dfs(i + 1, r)
+                dp[[l, r]] = max(dp[[l, r]]!, coins)
+            }
+
+            return dp[[l, r]]!
+        }
+
+        return dfs(1, nums.count - 2)
+    }
+}