41. 包含min函数的栈单调栈

Posted 2022-03-19 辉小歌

用一个单调栈，来维护。单调栈的栈头就是最小值。

class MinStack 
public:
    /** initialize your data structure here. */
    stack<int>minv;
    stack<int>st;
    MinStack() 
    
        
    
    
    void push(int x) 
        st.push(x);
        if(minv.empty() || minv.top()>=x) minv.push(x);
    
    
    void pop() 
        if(minv.top()==st.top()) minv.pop();
        st.pop();
    
    
    int top() 
        return st.top();
    
    
    int getMin() 
        return minv.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();
 */