Basit Stack Veri Yapısı

Design a stack that supports push, pop, top, and retrieving the minimum element in constant time.

https://leetcode.com/explore/featured/card/30-day-leetcoding-challenge/529/week-2/3292/
 

>> Solution 1 :Basit linked list, her node'da minimumu tut

	/**
	* Design a stack that supports push, pop, top, and retrieving the minimum element in constant time.
	* 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 {
	private Node top;
	public MinStack() {
	top = null;
	}
	public void push(int element) {
	top = new Node (element, top);
	}
	public void pop() {
	Node popped = top;
	top = top.next;
	}
	public int top() {
	return top.value;
	}
	public int getMin() {
	return top.minValue;
	}
	private class Node {
	int value;
	int minValue;
	Node next;
	Node(int value,Node next){
	this.value = value;
	this.next = next;
	if(next == null || value < next.minValue){
	minValue = value;
	} else {
	minValue = next.minValue;
	}
	}
	}
	}

view raw MinStack.java hosted with ❤ by GitHub

O(1) time complexity, O(n) space complexity