优先队列插入、删除

#include<stdio.h>
#include<malloc.h>
void shift_down(int a[], int low, int high)
{
    int i = low, j = i*2;
    int tmp = a[i];
    while(j <= high){
        if(j < high && a[j] < a[j+1])
            j++;
        if(tmp < a[j]){
            a[i] = a[j];
            i = j;
            j = i*2;
        }
        else break;
    }
    a[i] = tmp;
} 
void shift_up(int a[], int low, int high)
{
    int i = high/2, j = high;
    int tmp = a[high];
    while(i >= 1){
        if(a[i] < tmp){
            a[j] = a[i];
            j = i;
            i = j/2;
        }
        else break;
    }
    a[j] = tmp;
}
void print(int a[], int n)
{
    int i;
    for(i = 1; i <= n; i++){
        printf("%d ", a[i]);
    }
    printf("
");
}
int main()
{
    int n, i, a[110];
    scanf("%d", &n);
    for(i = 1; i <= n; i++){
        scanf("%d", &a[i]);
    }
    for(i = n/2; i >= 1; i--){
        shift_down(a, i, n);
    } //建立大顶堆 
    print(a, n);
    
    printf("删除大顶堆顶："); 
    a[1] = a[n];//删除当前最大元素 
    n--; 
    shift_down(a, 1, n);
    print(a, n); 
    
    printf("插入一个值："); 
    n++;
    scanf("%d", &a[n]);
    shift_up(a, 1, n);
    print(a, n);
    return 0;
} 
/*10
6 8 7 9 0 1 3 2 4 5*/