Problem:
MathJax.Hub.Config({ tex2jax: { inlineMath: [["$","$"], ["\\(","\\)"]], processEscapes: true }});

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>
#include <string.h>

int heap[2000001];
int have;

void up(int k)
{
	int save;
	while(k>1&&heap[k/2]<heap[k])
	{
		save=heap[k];
		heap[k]=heap[k/2];
		heap[k/2]=save;
		k=k/2;
	}
}

void down(int k)
{
	int i,save;
	while(2*k<=have)
	{
		i=2*k;
		if(i<have&&heap[i]<heap[i+1])
		{
			i++;
		}
		if(heap[k]>=heap[i])
		{
			break;
		}
		else
		{
			save=heap[k];
			heap[k]=heap[i];
			heap[i]=save;
			k=i;
		}
	}
}

void insert(int a)
{
	have++;
	heap[have]=a;
	up(have);
}

void extract()
{
	int save;
	if(have<1)
	{
		return;
	}
	save=heap[1];
	heap[1]=heap[have];
	heap[have]=save;
	have--;
	down(1);
	printf("%d\n",heap[have+1]);
	return;
}

int main(void)
{
	int N;
	int num;
	char get[10];
	have=0;

	while(1)
	{
		scanf("%s",get);
		if(strcmp(get,"end")==0)
		{
			break;
		}
		if(strcmp(get,"insert")==0)
		{
			scanf("%d",&num);
			insert(num);
		}
		if(strcmp(get,"extract")==0)
		{
			extract();
		}
	}


	return 0;
}