<p>Design a stack that supports increment operations on its elements.</p> <p>Implement the <code>CustomStack</code> class:</p> <ul> <li><code>CustomStack(int maxSize)</code> Initializes the object with <code>maxSize</code> which is the maximum number of elements in the stack.</li> <li><code>void push(int x)</code> Adds <code>x</code> to the top of the stack if the stack has not reached the <code>maxSize</code>.</li> <li><code>int pop()</code> Pops and returns the top of the stack or <code>-1</code> if the stack is empty.</li> <li><code>void inc(int k, int val)</code> Increments the bottom <code>k</code> elements of the stack by <code>val</code>. If there are less than <code>k</code> elements in the stack, increment all the elements in the stack.</li> </ul> <p> </p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input</strong> ["CustomStack","push","push","pop","push","push","push","increment","increment","pop","pop","pop","pop"] [[3],[1],[2],[],[2],[3],[4],[5,100],[2,100],[],[],[],[]] <strong>Output</strong> [null,null,null,2,null,null,null,null,null,103,202,201,-1] <strong>Explanation</strong> CustomStack stk = new CustomStack(3); // Stack is Empty [] stk.push(1); // stack becomes [1] stk.push(2); // stack becomes [1, 2] stk.pop(); // return 2 --> Return top of the stack 2, stack becomes [1] stk.push(2); // stack becomes [1, 2] stk.push(3); // stack becomes [1, 2, 3] stk.push(4); // stack still [1, 2, 3], Do not add another elements as size is 4 stk.increment(5, 100); // stack becomes [101, 102, 103] stk.increment(2, 100); // stack becomes [201, 202, 103] stk.pop(); // return 103 --> Return top of the stack 103, stack becomes [201, 202] stk.pop(); // return 202 --> Return top of the stack 202, stack becomes [201] stk.pop(); // return 201 --> Return top of the stack 201, stack becomes [] stk.pop(); // return -1 --> Stack is empty return -1. </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 <= maxSize, x, k <= 1000</code></li> <li><code>0 <= val <= 100</code></li> <li>At most <code>1000</code> calls will be made to each method of <code>increment</code>, <code>push</code> and <code>pop</code> each separately.</li> </ul>