heap c style

#include <cstdio>
#include <malloc.h>

struct heap {
    int size;
    int ind;
    int *mas;
};

heap *nheap(int size) {
    heap *h = (heap *) malloc(sizeof(heap));
    h->ind = 0;
    h->size = size;
    h->mas = (int *) (malloc(size*sizeof(int)));
    return h;
}

void sifting(heap *h, int ind) {
    int *mas = h->mas;
    if (ind == 0) {
        return;
    }
    if (ind & 1) {
        if (mas[ind] > mas[(ind - 1)/2]) {
            int t = mas[ind];
            mas[ind] = mas[(ind - 1)/2];
            mas[(ind - 1)/2] = t;
        }
        sifting(h, (ind - 1)/2);
    } else {
        if (mas[ind] > mas[ind/2 - 1]) {
            int t = mas[ind];
            mas[ind] = mas[ind/2 - 1];
            mas[ind/2 - 1] = t;
        }
        sifting(h, ind/2 - 1);
    }
}

void add_el_to_heap(heap *h, int element) {
    if (h->ind >= h->size) {
        h->size *= 2;
        int *nmas = (int *) realloc(h->mas, h->size*sizeof(int));
        if (nmas) {
            h->mas = nmas;
        }
    }
    h->mas[h->ind] = element;
    sifting(h, h->ind++);
}

void heapify(heap *h, int ind) {
    if (ind >= h->ind/2) {
        return;
    }
    int *mas = h->mas;
    int el = mas[ind];
    if (2*ind + 2 == h->ind) {
        if (el < mas[2*ind + 2]) {
            mas[ind] = mas[2*ind + 2];
            mas[2*ind + 2] = el;
        }
    } else {
        int maxind = (mas[2*ind + 1] > mas[2*ind + 2]) ? (2*ind + 1) : (2*ind + 2);
        mas[ind] = mas[maxind];
        mas[maxind] = el;
    }
}

int delmax(heap *h){
    if(h->ind == 0){
        return 0;
    }
    int *mas = h->mas;
    int max = mas[0];
    mas[0] = mas[--h->ind];
    heapify(h, 0);
    return max;
}

void printheap(heap *h) {
    for (int i = 0; i < h->ind; i++) {
        printf("%d ", h->mas[i]);
    }
    printf("\n");
}

int main() {
    heap *h = nheap(8);
    add_el_to_heap(h, 5);
    add_el_to_heap(h, 4);
    add_el_to_heap(h, 8);
    add_el_to_heap(h, 3);
    add_el_to_heap(h, 1);
    add_el_to_heap(h, 0);
    add_el_to_heap(h, 16);
    add_el_to_heap(h, 4);
    add_el_to_heap(h, 12);
    for(int i = 0; i < 9; i++){
        printf("%d ", delmax(h));
    }
}