The problem involves designing a stack with a custom increment operation. The stack should support basic stack operations like push and pop, and an additional increment operation that increments the bottom elements of the stack by a given value.

Problem

Implement a stack with the following operations:

• push(int x): Push element x onto stack.
• pop(): Removes the element on top of the stack and returns it.
• increment(int k, int val): Increments the bottom k elements of the stack by val.

Input

• int[] ops: An array of operations where each operation is either "PUSH x", "POP", or "INCREMENT k val".
• int k and int val: Parameters for the increment operation.

Output

• The top element of the stack after all operations are performed.

Constraints

• 1 <= n <= 100 where n is the number of operations.
• -100 <= val <= 100.
• 1 <= k <= n.
• 1 <= x <= 100 for push operations.

Test Cases

• Example 1:
  • Input: n = 5, ops = ["PUSH 1", "PUSH 2", "PUSH 3", "POP", "POP"]
  • Output: 2
• Example 2:
  • Input: n = 4, ops = ["PUSH 1", "PUSH 2", "PUSH 3", "POP"]
  • Output: 1