155_Min_Stack.cpp

#include<vector>
#include<cstring>
#include<iostream>
#include<stack>

using namespace std;


class MinStack {
public:
	stack<int> s, s_min;
	/** initialize your data structure here. */
	MinStack() {

	}

	void push(int x) {
		s.push(x);
		if (s_min.empty() || s_min.top() >= x) {
			s_min.push(x);
		}
	}

	void pop() {
		if (s.top() == s_min.top()) {
			s_min.pop();
		}
		s.pop();
	}

	int top() {
		return s.top();
	}

	int getMin() {
		return s_min.top();
	}
};

/**
 * 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();
 */