STL优先队列

priority_queue< int, vector< int >, greater< int > > qi2;
从小到大的优先级队列，可将greater改为less，即为从大到小
for(i = 0; i < len; i++)
qi2.push(a[i]);
for(i = 0; i < len; i++)
{
cout< < qi2.top() < <” “;
qi2.pop();
}

与pair的结合

typedef pair<int, int> P;priority_queue< P, vector<P>, greater<P> > Q;struct Order{    bool operator()(P const& a, P const& b) const    {        return a.second < b.second || a.second == b.second &&a.first < b.first;    }}  //自己的比较算子