coding/algorithm/Stack/minStack/MinStack.java at master · orcl/coding · GitHub

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public class MinStack {

Stack<Integer> s1 = new Stack<Integer>();

Stack<Integer> s2 = new Stack<Integer>();

public void push(int x) {

s1.push(x);

if (x <= min) {

s2.push(x);

min = x;

}

}

public void pop() {

int tmp = s1.pop();

if (tmp == min) {

s2.pop();

if (!s2.isEmpty())

min = s2.peek();

else

min = Integer.MAX_VALUE;

}

}

public int top() {

return s1.peek();

}

}//end class MinStack