剑指offer速通

栈

1.剑指 Offer 30. 包含min函数的栈 - 力扣（LeetCode） (leetcode-cn.com)

class MinStack {
    stack<int >sm ,s;
public:
    /** initialize your data structure here. */
    MinStack() {
        while(!sm.empty()){
            sm.pop();
        }
        while(!s.empty()){
            s.pop();
        }
    }
    
    void push(int x) {
        s.push(x);
        if(sm.empty()||x<=sm.top()){
            sm.push(x);
        }
    }
    
    void pop() {
        if(sm.top()==s.top()){
            sm.pop();
        }
        s.pop();
        
    }
    
    int top() {
        return s.top();
    }
    
    int min() {
        return sm.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->min();
 */