#1381
Design a Stack With Increment Operation
pupil · 440 · lc medium +26 · 79.9% accepted · 2,365 likes · top 91%
Description
Design a bounded stack with a bulk increment operation. Implement CustomStack:
- CustomStack(int maxSize) Creates a stack with capacity maxSize.
- void push(int x) Pushes x onto the stack only if it has not yet reached capacity.
- int pop() Removes and returns the top element, or -1 if the stack is empty.
- void inc(int k, int val) Adds val to the bottom k elements; if fewer than k elements exist, increments all of them.
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 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.
Code
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20