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 <= 10001 <= x <= 10001 <= k <= 10000 <= val <= 1001000 calls will be made to each method of increment,
push and pop each separately.