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>

#define N 2000000
#define INF 2000000000

void maxHeapify(int *, int);
int heapExtractMax(int *);
void maxHeapInsert(int *, int);
void heapIncreaseKey(int *, int, int);

int h = 0;

int main() {
  int  i, key, data[N];
  char s[8];

while(1) {
    scanf("%s", s);

    if (s[0] == 'i') {
        scanf("%d", &key);
        maxHeapInsert(data, key);
    }
    else if (s[0] == 'e' && s[1] == 'x') {
     printf("%d\n", heapExtractMax(data));
    }
    else if (s[0] == 'e' && s[1] == 'n') {
      break;
    }
  }
  return 0;
}


void maxHeapify(int *d, int i) {
  int l, r, largest, temp;
  
  l = i * 2;
  r = i * 2 + 1;

  if (l <= h && d[l] > d[i]) largest = l;
  else largest = i;

  if (r <= h && d[r] > d[largest]) largest = r;

  if (largest != i) {
    temp = d[i];
    d[i] = d[largest];
    d[largest] = temp;
    maxHeapify(d, largest);
  }
}

int heapExtractMax(int *d) {
    int max;
    if (h < 1) return -INF;
    max = d[1];
    d[1] = d[h];
    h--;
    maxHeapify(d, 1);
    return max;
}


void maxHeapInsert(int *d, int key) {
    h++;
    d[h] = -INF;
    heapIncreaseKey(d, key, h);
}


void heapIncreaseKey(int *d, int key, int i) {
    int temp;
    if (key < d[i]) return;
    d[i] = key;
    while(i > 1 && d[i / 2] < d[i]) {
        temp = d[i];
        d[i] = d[i / 2];
        d[i / 2] = temp;
        i = i / 2;
    }
}