MinStack

gistfile1.txt

function MinStack(){
    this.stack = [];
    this.min = [];
}

MinStack.prototype.push = function(x){
    if(this.stack.length==0){
        this.min.push(x);
    }else{
        if(this.getMin()>x){
            this.min.push(x);
        }else{
            this.min.push(this.getMin());
        }
    }
    this.stack.push(x);
}

MinStack.prototype.pop = function(){
    this.min.pop();
    return this.stack.pop();
}

MinStack.prototype.getMin = function(){
    return this.min[this.min.length-1];
}

var stack = new MinStack();

stack.push(3);
stack.push(5);
console.log(stack.getMin());
stack.push(4);
console.log(stack.getMin());
stack.push(1);
console.log(stack.getMin());
stack.pop();
console.log(stack.getMin());
stack.pop();
console.log(stack.getMin());