MinStackleetcode Min Stack
Design a stack that supports push, pop, top, and retrieving the minimum element in constant time.push(x) -- Push element x onto stack.pop() -- Removes the element on top of the stack.top() -- Get the top element.getMin() -- Retrieve the minimum element in the stack.
class MinStack { PRivate Stack<Integer> stack; private Stack<Integer> min; //存储最小数的栈 public MinStack() { stack = new Stack<Integer>(); min = new Stack<Integer>(); } public void push(int x) { if (min.isEmpty() || min.peek()>=x) min.push(x); stack.push(x); } public void pop() { if (stack.peek().equals(min.peek())) min.pop(); stack.pop(); } public int top() { return stack.peek(); } public int getMin() { return min.peek(); }}