g1401_1500.s1441_build_an_array_with_stack_operations

Class Solution

java.lang.Object

g1401_1500.s1441_build_an_array_with_stack_operations.Solution

public class Solution
extends Object

1441 - Build an Array With Stack Operations.

Easy

You are given an array target and an integer n.

In each iteration, you will read a number from list = [1, 2, 3, ..., n].

Build the target array using the following operations:

• "Push": Reads a new element from the beginning list, and pushes it in the array.
• "Pop": Deletes the last element of the array.
• If the target array is already built, stop reading more elements.

Return a list of the operations needed to build target. The test cases are generated so that the answer is unique.

Example 1:

Input: target = [1,3], n = 3

Output: [“Push”,“Push”,“Pop”,“Push”]

Explanation:

Read number 1 and automatically push in the array -> [1]

Read number 2 and automatically push in the array then Pop it -> [1]

Read number 3 and automatically push in the array -> [1,3]

Example 2:

Input: target = [1,2,3], n = 3

Output: [“Push”,“Push”,“Push”]

Example 3:

Input: target = [1,2], n = 4

Output: [“Push”,“Push”]

Explanation: You only need to read the first 2 numbers and stop.

Constraints:

• 1 <= target.length <= 100
• 1 <= n <= 100
• 1 <= target[i] <= n
• target is strictly increasing.

Constructor Summary

Constructors

Constructor and Description
Solution()

Method Summary

Modifier and Type	Method and Description
List<String>	buildArray(int[] target, int n)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Solution

public Solution()

Method Detail

buildArray

public List<String> buildArray(int[] target,
                               int n)