LeetCode/_155_MinStack.java at main · SinghAnna/LeetCode · GitHub

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import java.util.Stack;

class MinStack {


    Stack<Integer> stack;
    Stack<Integer> minStack;

    public MinStack() {
       stack = new Stack<>();
       minStack =  new Stack<>();
    }

    public void push(int val) {
        stack.push(val);

        if (minStack.isEmpty()) {
            minStack.push(val);
        }else{
            minStack.push(Math.min(val, minStack.peek()));
        }
    }

    public void pop() {
        stack.pop();
        minStack.pop();
    }

    public int top() {
       return stack.peek();
    }

    public int getMin() {
        return minStack.peek();
    }
}


public class _155_MinStack {
    public static void main(String[] args) {
        MinStack minStack = new MinStack();
        minStack.push(-2);
        minStack.push(0);
        minStack.push(-3);
        System.out.println(minStack.getMin());
        minStack.pop();
        System.out.println(minStack.top());
        System.out.println(minStack.getMin());
    }
}