minStack.js

////////////////////////////////////////////////Min Stack///////////////////////////////////////////////
// Design a stack that supports push, pop, top, and retrieving the minimum element in constant time.
// Implement the MinStack class:
// MinStack() initializes the stack object.
// void push(int val) pushes the element val onto the stack.
// void pop() removes the element on the top of the stack.
// int top() gets the top element of the stack.
// int getMin() retrieves the minimum element in the stack.
// Example 1:
// Input
// ["MinStack","push","push","push","getMin","pop","top","getMin"]
// [[],[-2],[0],[-3],[],[],[],[]]
// Output
// [null,null,null,null,-3,null,0,-2]
// Explanation
// MinStack minStack = new MinStack();
// minStack.push(-2);
// minStack.push(0);
// minStack.push(-3);
// minStack.getMin(); // return -3
// minStack.pop();
// minStack.top();    // return 0
// minStack.getMin(); // return -2
const MinStack = function() {
    this.data = []
};

/**
 * @param {number} val
 * @return {void}
 */
MinStack.prototype.push = function(val) {
    this.data.push(val);
};

/**
 * @return {void}
 */
MinStack.prototype.pop = function() {
    return this.data.pop();
};

/**
 * @return {number}
 */
MinStack.prototype.top = function() {
    return this.data[this.data.length -1];
};

/**
 * @return {number}
 */
MinStack.prototype.getMin = function() {
    return Math.min(...this.data)
};

/**
 * Your MinStack object will be instantiated and called as such:
 * var obj = new MinStack()
 * obj.push(val)
 * obj.pop()
 * var param_3 = obj.top()
 * var param_4 = obj.getMin()
 */