Problem:
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Priority Queue

A priority queue is a data structure which maintains a set $S$ of elements, each of with an associated value (key), and supports the following operations:

$insert(S, k)$: insert an element $k$ into the set $S$

$extractMax(S)$: remove and return the element of $S$ with the largest key

Write a program which performs the $insert(S, k)$ and $extractMax(S)$ operations to a priority queue $S$.
The priority queue manages a set of integers, which are also keys for the priority.

Input

Multiple operations to the priority queue $S$ are given. Each operation is given by "insert $k$", "extract" or "end" in a line. Here, $k$ represents an integer element to be inserted to the priority queue.

The input ends with "end" operation.

Output

For each "extract" operation, print the element extracted from the priority queue $S$ in a line.

Constraints

The number of operations $\leq 2,000,000$

$0 \leq k \leq 2,000,000,000$

Sample Input 1

insert 8
insert 2
extract
insert 10
extract
insert 11
extract
extract
end

Sample Output 1

8
10
11
2

Solution in C (judge verdict: Accepted)

#include<stdio.h>
int q[2000000];
void swap(int i, int j){

  int tmp;

  tmp=q[i];
  q[i]=q[j];
  q[j]=tmp;

}//swap

int main(){
  int k,s=0;
  int i,pr,l, r;
  char A[2];
  while(1){
    scanf("%s%d",A,&k);
    if(A[0]=='i'){
      i=s;
      q[i]=k;
      while(i>0 && q[i]>q[pr=(i-1)/2]){
          swap(i,pr);
          i=pr;
        }
        ++s;
    }
    else if(A[1]=='n')break;
    else{
      printf("%d\n",q[0]);

      q[i=0]=q[--s];
      --q[s];
      while((l=i*2+1)<s){
        if((r=l+1)<s && q[r] > q[l])l=r;
        if(q[i]<q[l])swap(i,l);
        i=l;
      }
    }
  }
  return 0;
}//main