heap?

// minheap

#include<stdio.h>

#include<stdlib.h>

#define MAX_ELEMENTS 200  /* maximum heap size+l */

#define HEAP_FULL(n) (n == MAX_ELEMENTS - 1)

#define HEAP_EMPTY(n) (!n)

typedef struct {

int key;

char name[20];

/* other fields */

} element;

element heap[MAX_ELEMENTS];

int n = 0;

element pop(int *n);

void push(element item, int *n);

int main(void)

{

char choice;

element put;

for(;;)

{

printf("자료를 입력하시오. (num, name)\n");

scanf("%d",&put.key);

if(put.key==-1)

break;

scanf("%s",&put.name);

push(put,&n);

}

for(;;)

{

getchar();

printf("Root 노드의 레코드를 삭제할까요 ? : ");

scanf("%c",&choice);

if(choice=='y')

{

put=pop(&n);

printf("<%d,%s>\n",put.key,put.name);

}

else break;

}

return 0;

}

void push(element item, int *n)

{

int i;

if (HEAP_FULL(*n)) {

fprintf(stderr, "The heap is full. \n");

exit(EXIT_FAILURE);

}

i = ++(*n);

while ((i != 1) && (item.key < heap[i/2].key)) {

heap[i] = heap[i/2];

i /= 2;

}

heap[i] = item;

}

element pop(int *n)

{

int parent, child;

element item, temp;

if (HEAP_EMPTY(*n)) {

fprintf(stderr, "The heap is empty\n");

exit(EXIT_FAILURE);

}

item = heap[1];

temp = heap[( *n)--] ;

parent = 1;

child = 2;

while (child <= *n) {

if ((child < *n) && (heap[child].key > heap[child+1].key)) child++;

if (temp.key <= heap[child].key) break;

heap[parent] = heap[child];

parent = child;

child *= 2;

}

heap[parent] = temp;

return item;

}