295. 数据流的中位数

//295. 数据流的中位数
class MedianFinder {
public:
    /** initialize your data structure here. */
    MedianFinder() {
        
    }
    
    void addNum(int num) {
        auto m=small.size(),n=big.size();
        if(small.empty()){
            small.push(num);
            return;
        }
        if(m==n){
            auto s=small.top(),b=big.top();
            if(s<num)
                big.push(num);
            else small.push(num);
        }
        else if(m>n){
            if(small.top()<num)
                big.push(num);
            else 
            {   
                auto t=small.top();
                small.pop();
                small.push(num);
                big.push(t);
            }
        }
        else if(m<n){
            if(big.top()>num)
                small.push(num);
            else 
            {
                auto t=big.top();
                small.push(t);
                big.pop();
                big.push(num);
            }
        }
    }
    
    double findMedian() {
        auto m=small.size(),n=big.size();
        if(m==n)
            return (small.top()+big.top())/2.0;
        else if(m>n)
            return small.top();
        return big.top();
    }
private:
    priority_queue<int>small;
    priority_queue<int,vector<int>,greater<int>>big;
};

/**
 * Your MedianFinder object will be instantiated and called as such:
 * MedianFinder obj = new MedianFinder();
 * obj.addNum(num);
 * double param_2 = obj.findMedian();
 */