java.lang.Object
g1401_1500.s1441_build_an_array_with_stack_operations.Solution

public class Solution extends java.lang.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
    Description
     
  • Method Summary

    Modifier and Type
    Method
    Description
    java.util.List<java.lang.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 Details

    • Solution

      public Solution()
  • Method Details

    • buildArray

      public java.util.List<java.lang.String> buildArray(int[] target, int n)