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Min Stack

Problem statement

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]ExplanationMinStack minStack = new MinStack();minStack.push(-2);minStack.push(0);minStack.push(-3);minStack.getMin(); // return -3minStack.pop();minStack.top();    // return 0minStack.getMin(); // return -2

Constraints:

  • -231 <= val <= 231 - 1
  • Methods pop, top and getMin operations will always be called on non-empty stacks.
  • At most 3 * 104 calls will be made to push, pop, top, and getMin.

My solution

/**
* initialize your data structure here.
*/
var MinStack = function() {
this.sorted = []
this.stack = [];
};

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

this.sort();

};

MinStack.prototype.sort = function() {
this.sorted = [...this.stack].sort((a, b) => a - b);
console.log(this.sorted);
}

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

this.sort();
};

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

/**
* @return {number}
*/
MinStack.prototype.getMin = function() {
return this.sorted[0];
};

/**
* 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.getMin()
*/