设计一个支持 push ，pop ，top 操作，并能在常数时间内检索到最小元素的栈。push(x) —— 将元素 x 推入栈中。pop() —— 删除栈顶的元素。top() —— 获取栈顶元素。getMin() —— 检索栈中的最小元素。 示例:输入：["MinStack","push","push","push","getMin","pop","top","getMin"][[],[-2],[0],[-3],[],[],[],[]]输出：[null,null,null,null,-3,null,0,-2]解释：MinStack minStack = new MinStack();minStack.push(-2);minStack.push(0);minStack.push(-3);minStack.getMin();   --> 返回 -3.minStack.pop();minStack.top();      --> 返回 0.minStack.getMin();   --> 返回 -2. 提示：pop、top 和 getMin 操作总是在 非空栈 上调用。

/** * initialize your data structure here. */var MinStack = function() {    this.stack = []    this.minStack = []};/** * @param {number} x * @return {void} */MinStack.prototype.push = function(x) {    this.stack.push(x)    if (this.minStack.length == 0 ||  x <= this.minStack[this.minStack.length - 1]) {        this.minStack.push(x)    }};/** * @return {void} */MinStack.prototype.pop = function() {    const x = this.stack.pop()    if (x !== void 0 &&  x === this.minStack[this.minStack.length - 1]) {        this.minStack.pop()    }};/** * @return {number} */MinStack.prototype.top = function() {    return this.stack[this.stack.length - 1]};/** * @return {number} */MinStack.prototype.min = function() {    return this.minStack[this.minStack.length - 1]};/** * Your MinStack object will be instantiated and called as such: * var obj = new MinStack() * obj.push(x) * obj.pop() * var param_3 = obj.top() * var param_4 = obj.min() */

class MinStack {    stack<int> data;    stack<int> helper;public:    /** initialize your data structure here. */    MinStack() {    }    void push(int x) {        data.push(x);        if(helper.empty() || helper.top() >= x)        {            helper.push(x);        }    }    void pop() {        int top = data.top();        data.pop();        if(top == helper.top())        {            helper.pop();        }    }    int top() {        return data.top();    }    int getMin() {        return helper.top();    }};/** * Your MinStack object will be instantiated and called as such: * MinStack* obj = new MinStack(); * obj->push(x); * obj->pop(); * int param_3 = obj->top(); * int param_4 = obj->getMin(); */

public class MinStack {    // 数据栈    private Stack<Integer> data;    // 辅助栈    private Stack<Integer> helper;    /**     * initialize your data structure here.     */    public MinStack() {        data = new Stack<>();        helper = new Stack<>();    }    public void push(int x) {        // 辅助栈在必要的时候才增加        data.add(x);        if (helper.isEmpty() || helper.peek() >= x) {            helper.add(x);        }    }    public void pop() {        // 关键 3：data 一定得 pop()        if (!data.isEmpty()) {            // 注意：声明成 int 类型，这里完成了自动拆箱，从 Integer 转成了 int，            // 因此下面的比较可以使用 "==" 运算符            int top = data.pop();            if(top == helper.peek()){                helper.pop();            }        }    }    public int top() {        if(!data.isEmpty()){            return data.peek();        }    }    public int getMin() {        if(!helper.isEmpty()){            return helper.peek();        }    }}

class MinStack:    def __init__(self):        """        initialize your data structure here.        """        self.stack = []        self.minstack = []    def push(self, x: int) -> None:        self.stack.append(x)        if not self.minstack or x <= self.minstack[-1]:            self.minstack.append(x)    def pop(self) -> None:        tmp = self.stack.pop()        if tmp == self.minstack[-1]:            self.minstack.pop()    def top(self) -> int:        return self.stack[-1]    def min(self) -> int:        return self.minstack[-1]# Your MinStack object will be instantiated and called as such:# obj = MinStack()# obj.push(x)# obj.pop()# param_3 = obj.top()# param_4 = obj.min()

/* * @lc app=leetcode id=155 lang=javascript * * [155] Min Stack *//** * initialize your data structure here. */var MinStack = function() {  this.stack = [];  this.minV = Number.MAX_VALUE;};/** * @param {number} x * @return {void} */MinStack.prototype.push = function(x) {  // update 'min'  const minV = this.minV;  if (x < this.minV) {    this.minV = x;  }  return this.stack.push(x - minV);};/** * @return {void} */MinStack.prototype.pop = function() {  const item = this.stack.pop();  const minV = this.minV;  if (item < 0) {    this.minV = minV - item;    return minV;  }  return item + minV;};/** * @return {number} */MinStack.prototype.top = function() {  const item = this.stack[this.stack.length - 1];  const minV = this.minV;  if (item < 0) {    return minV;  }  return item + minV;};/** * @return {number} */MinStack.prototype.min = function() {  return this.minV;};/** * Your MinStack object will be instantiated and called as such: * var obj = new MinStack() * obj.push(x) * obj.pop() * var param_3 = obj.top() * var param_4 = obj.min() */

class MinStack {    stack<long> data;    long min = INT_MAX;public:    /** initialize your data structure here. */    MinStack() {    }    void push(int x) {        data.push(x - min);        if(x < min)        {            min = x;        }    }    void pop() {        long top = data.top();        data.pop();        // 更新最小值        if(top < 0)        {            min -= top;        }    }    int top() {        long top = data.top();        // 最小值为 min        if (top < 0)        {            return min;        }        else{            return min+top;        }    }    int getMin() {        return min;    }};/** * Your MinStack object will be instantiated and called as such: * MinStack* obj = new MinStack(); * obj->push(x); * obj->pop(); * int param_3 = obj->top(); * int param_4 = obj->getMin(); */

class MinStack {    long min;    Stack<Long> stack;    /** initialize your data structure here. */    public MinStack() {        stack = new Stack<>();    }    public void push(int x) {        if (stack.isEmpty()) {            stack.push(0L);            min = x;        }        else {            stack.push(x - min);            if (x < min)                min = x;        }    }    public void pop() {        long p = stack.pop();        if (p < 0) {            // if (p < 0), the popped value is the min            // Recall p is added by this statement: stack.push(x - min);            // So, p = x - old_min            // old_min = x - p            // again, if (p < 0), x is the min so:            // old_min = min - p            min = min - p;        }    }    public int top() {        long p = stack.peek();        if (p < 0) {            return (int) min;        }        else {            // p = x - min            // x = p + min            return (int) (p + min);        }    }    public int getMin() {        return (int) min;    }}

class MinStack:    def __init__(self):        """        initialize your data structure here.        """        self.minV = float('inf')        self.stack = []    def push(self, x: int) -> None:        self.stack.append(x - self.minV)        if x < self.minV:            self.minV = x    def pop(self) -> None:        if not self.stack:            return        tmp = self.stack.pop()        if tmp < 0:            self.minV -= tmp    def top(self) -> int:        if not self.stack:            return        tmp = self.stack[-1]        if tmp < 0:            return self.minV        else:            return self.minV + tmp    def min(self) -> int:        return self.minV# Your MinStack object will be instantiated and called as such:# obj = MinStack()# obj.push(x)# obj.pop()# param_3 = obj.top()# param_4 = obj.min()