int heap[MAX_N],int sz=0;void push(int x){    int i=sz++;    while(i>0)    {        int p=(i-1)/2;//得到父节点        if(heap[p]<=x) break;        heap[i]=heap[p];        i=p;    }    heap[i]=x;}int pop(){    int ret=heap[0];    int x=heap[--sz];    int i=0;    while(i*2+1
     
      =x) break;        heap[a]=x;        i=a;    }    heap[i]=x;    return ret;}