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>
#define MAX 2000000
#define INFTY (1<<30)
int H , A[MAX+1];


void maxHeapify(int i)
{
	int tmp;
	int l , r , largest;
	l = 2*i;
	r = 2*i+1;
	
	if( l <= H && A[l] > A[i]) largest = l;
	else largest = i;
	if(r <= H && A[r] > A[largest] ) largest = r;
	
	if(largest != i)
	{
		tmp = A[i];
		A[i] = A[largest];
		A[largest] = tmp;
		maxHeapify(largest);
	}
}

int extract()
{
	int maxv;
	if( H < 1 ) return -INFTY;
	maxv = A[1];
	A[1] = A[H--];
	maxHeapify(1);
	return maxv;
}

void increaseKey(int i , int key)
{
	int tmp;
	if(key < A[i]) return;
	A[i] = key;
	while(i > 1 && A[i/2] < A[i])
	{
		tmp = A[i];
		A[i] = A[i/2];
		A[i/2] = tmp;
		i = i / 2;
	}
}

void insert(int key)
{
	H++;
	A[H] = -INFTY;
	increaseKey(H,key);
}
int main(void)
{
	int key;
	char com[10];
	
	while(1)
	{
		scanf("%s",com);
		if(com[0] == 'e' && com[1] == 'n') break;
		if( com[0] == 'i')
		{
			scanf("%d",&key);
			insert(key);
		}
		else{
			printf("%d\n",extract());
		}
	}
	return 0;
}