Fruit Into Baskets

Author: gouthampradhan

README.md

@@ -14,6 +14,7 @@ My accepted leetcode solutions to some of the common interview problems.
 - [Can Place Flowers](problems/src/array/CanPlaceFlowers.java) (Easy)
 - [Merge Intervals](problems/src/array/MergeIntervals.java) (Medium)
 - [First Missing Positive](problems/src/array/FirstMissingPositive.java) (Hard)
+- [Fruit Into Baskets](problems/src/array/FruitIntoBaskets.java) (Medium)
 - [MaxProduct Of Three Numbers](problems/src/array/MaxProductOfThreeNumbers.java) (Easy)
 - [Missing Number](problems/src/array/MissingNumber.java) (Easy)
 - [Merge Sorted Array](problems/src/array/MergeSortedArray.java) (Easy)

problems/src/array/FruitIntoBaskets.java

@@ -0,0 +1,100 @@
+package array;
+
+import java.util.Stack;
+
+/**
+ * Created by gouthamvidyapradhan on 02/03/2019
+ * In a row of trees, the i-th tree produces fruit with type tree[i].
+ *
+ * You start at any tree of your choice, then repeatedly perform the following steps:
+ *
+ * Add one piece of fruit from this tree to your baskets.  If you cannot, stop.
+ * Move to the next tree to the right of the current tree.  If there is no tree to the right, stop.
+ * Note that you do not have any choice after the initial choice of starting tree: you must perform step 1, then step 2, then back to step 1, then step 2, and so on until you stop.
+ *
+ * You have two baskets, and each basket can carry any quantity of fruit, but you want each basket to only carry one type of fruit each.
+ *
+ * What is the total amount of fruit you can collect with this procedure?
+ *
+ *
+ *
+ * Example 1:
+ *
+ * Input: [1,2,1]
+ * Output: 3
+ * Explanation: We can collect [1,2,1].
+ * Example 2:
+ *
+ * Input: [0,1,2,2]
+ * Output: 3
+ * Explanation: We can collect [1,2,2].
+ * If we started at the first tree, we would only collect [0, 1].
+ * Example 3:
+ *
+ * Input: [1,2,3,2,2]
+ * Output: 4
+ * Explanation: We can collect [2,3,2,2].
+ * If we started at the first tree, we would only collect [1, 2].
+ * Example 4:
+ *
+ * Input: [3,3,3,1,2,1,1,2,3,3,4]
+ * Output: 5
+ * Explanation: We can collect [1,2,1,1,2].
+ * If we started at the first tree or the eighth tree, we would only collect 4 fruits.
+ *
+ *
+ * Note:
+ *
+ * 1 <= tree.length <= 40000
+ * 0 <= tree[i] < tree.length
+ *
+ */
+public class FruitIntoBaskets {
+
+    private int count = 0;
+    private int max = 0;
+    /**
+     * Main method
+     * @param args
+     */
+    public static void main(String[] args) {
+        int[] trees = {1, 0, 3, 4, 3};
+        System.out.println(new FruitIntoBaskets().totalFruit(trees));
+    }
+
+    public int totalFruit(int[] tree) {
+        int t1 = -1, t2 = -1;
+        Stack<Integer> stack = new Stack<>();
+        for(int i : tree){
+           if(i == t1 || i == t2){
+               countAndMax(stack, i);
+           } else {
+               if(t1 == -1){
+                   t1 = i;
+                   countAndMax(stack, i);
+               } else if(t2 == -1){
+                   t2 = i;
+                   countAndMax(stack, i);
+               } else{
+                   Stack<Integer> temp = new Stack<>();
+                   count = 0;
+                   t1 = stack.pop();
+                   countAndMax(temp, t1);
+                   while(!stack.isEmpty() && stack.peek() == t1){
+                       countAndMax(temp, stack.pop());
+                   }
+                   t2 = i;
+                   stack = temp;
+                   countAndMax(stack, i);
+               }
+           }
+        }
+        return max;
+    }
+
+    private void countAndMax(Stack<Integer> stack, int i){
+        count++;
+        stack.push(i);
+        max = Math.max(max, count);
+    }
+}