LeetCode: Min Stack

LeetCode: Min Stack

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/**
* Created by hzhou on 4/24/15. [email protected]
*/
public class MinStack {
private Stack<Integer> stack = new Stack<Integer>();
private Stack<Integer> minStack = new Stack<Integer>();
public void push(int x) {
stack.push(x);
if (minStack.isEmpty() || x <= minStack.peek()) {
minStack.push(x);
}
}
public void pop() {
int val = stack.pop();
if (val <= minStack.peek()) {
minStack.pop();
}
}
public int top() {
return stack.peek();
}
public int getMin() {
return minStack.peek();
}
}