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>
#include<string.h>
#define MAX 2000000
#define INFTY (1<<30)

int H,A[MAX +1];
void swap(int a,int b){
		int dmp;
		dmp = A[a];
		A[a] = A[b];
		A[b] = dmp;
	
}
void maxHeapify(int i){
	int l,r,largest;
	l = 2 * i;
	r = 2 * i + 1;
	int dmp = 0;
	if(l <= H && A[l] > A[i]){
		largest = l;
	}
	else {
		largest = i;
	}
	if(r <= H && A[r] > A[largest]){
		largest = r;
	}
	
	if(largest != i){
		
		swap(i,largest);
		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){
	
	if(key < A[i])return;
	A[i] = key;
	while(i > 1&&A[i / 2] < A[i]){
		swap(i,i/2);
		i = i/2;
	}
}

void insert(int key){
	H++;
	A[H] = -INFTY;
	increaseKey(H,key);
	
}
int main (){
	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;
	
}