Package g1301_1400.s1381_design_a_stack_with_increment_operation

Class CustomStack

java.lang.Object
g1301_1400.s1381_design_a_stack_with_increment_operation.CustomStack
public class CustomStack extends java.lang.Object
1381 - Design a Stack With Increment Operation.

Medium

Design a stack which supports the following operations.

Implement the CustomStack class:

  • CustomStack(int maxSize) Initializes the object with maxSize which is the maximum number of elements in the stack or do nothing if the stack reached the maxSize.
  • void push(int x) Adds x to the top of the stack if the stack hasn’t reached the maxSize.
  • int pop() Pops and returns the top of stack or -1 if the stack is empty.
  • void inc(int k, int val) Increments the bottom k elements of the stack by val. If there are less than k elements in the stack, just increment all the elements in the stack.

Example 1:

Input

[“CustomStack”,“push”,“push”,“pop”,“push”,“push”,“push”,“increment”,“increment”,“pop”,“pop”,“pop”,“pop”]

[[3],[1],[2],[],[2],[3],[4],[5,100],[2,100],[],[],[],[]]

Output: [null,null,null,2,null,null,null,null,null,103,202,201,-1]

Explanation:

 CustomStack customStack = new CustomStack(3); // Stack is Empty []
 customStack.push(1); // stack becomes [1]
 customStack.push(2); // stack becomes [1, 2]
 customStack.pop(); // return 2 --> Return top of the stack 2, stack becomes [1]
 customStack.push(2); // stack becomes [1, 2]
 customStack.push(3); // stack becomes [1, 2, 3]
 customStack.push(4); // stack still [1, 2, 3], Don't add another elements as size is 4
 customStack.increment(5, 100); // stack becomes [101, 102, 103]
 customStack.increment(2, 100); // stack becomes [201, 202, 103]
 customStack.pop(); // return 103 --> Return top of the stack 103, stack becomes [201, 202]
 customStack.pop(); // return 202 --> Return top of the stack 102, stack becomes [201]
 customStack.pop(); // return 201 --> Return top of the stack 101, stack becomes []
 customStack.pop(); // return -1 --> Stack is empty return -1.

Constraints:

  • 1 <= maxSize <= 1000
  • 1 <= x <= 1000
  • 1 <= k <= 1000
  • 0 <= val <= 100
  • At most 1000 calls will be made to each method of increment, push and pop each separately.

  • Constructor Summary

    Constructors
    Constructor
    Description
    CustomStack(int maxSize)
     

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    increment(int k, int val)
     
    int
    pop()
     
    void
    push(int x)
     

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • CustomStack

      public CustomStack(int maxSize)

  • Method Details

    • push

      public void push(int x)

    • pop

      public int pop()

    • increment

      public void increment(int k, int val)