Create Burst Balloons.java

Author: Sakshamgupta90

LeetCode/Burst Balloons.java

@@ -0,0 +1,56 @@
+   // Leetcode Ques No. : 312
+   // Problem Link: https://leetcode.com/problems/burst-balloons/
+
+
+   ***** problem statement *****
+
+   /*
+    You are given n balloons, indexed from 0 to n - 1. Each balloon is painted with a number on it represented by an array nums. You are asked to burst all the balloons.
+
+    If you burst the ith balloon, you will get nums[i - 1] * nums[i] * nums[i + 1] coins. If i - 1 or i + 1 goes out of bounds of the array, then treat it as if there is a balloon with a 1 painted on it.
+
+    Return the maximum coins you can collect by bursting the balloons wisely.
+
+
+   */
+
+
+   ***** Solution *****
+
+
+
+    public int maxCoins_memo(int[] nums , int si , int ei , int[][] dp){ //si = starting index , ei = ending index
+        if(dp[si][ei] != 0)
+            return dp[si][ei];
+        
+        int lele = si == 0 ? 1 : nums[si - 1]; //lele = leftelement
+        int rele = ei == nums.length - 1 ? 1 : nums[ei + 1]; //rele = rightelement
+        
+        int maxCoin = 0;
+        for(int cut = si; cut <= ei; cut++){
+            int lcost = cut == si ? 0 : maxCoins_memo(nums , si , cut - 1 , dp); //lcost:leftcost
+            int rcost = cut == ei ? 0 : maxCoins_memo(nums , cut + 1 , ei , dp); //rcost:rightcost
+            
+            maxCoin = Math.max(maxCoin , lcost + lele * nums[cut] * rele + rcost);
+        }
+        
+        return dp[si][ei] = maxCoin;
+    }
+    public int maxCoins(int[] nums) {
+        int n = nums.length;
+        int[][] dp = new int[n][n];
+        
+        return maxCoins_memo(nums , 0 , n - 1 , dp);
+    }
+
+
+
+
+
+   /*
+    Sample input: [3,1,5,8]
+                  
+    Sample Output: 167
+    
+    
+    */