Priority Queue

#include <stdio.h>
#include <stdlib.h>
using namespace std;
class Priority_Queue{
private:
    int *DATA;
    int capacity;
    int size;
    void SWAP(int* A, int* B){
        int temp = *A;
        *A = *B;
        *B = temp;
    }
public:
    Priority_Queue(int c) : capacity(c) {
        DATA = (int*)malloc(sizeof(int)*capacity);
        size = 1;
    };
    Priority_Queue() {
        capacity = 10;
        DATA = (int*)malloc(sizeof(int)*capacity);
        size = 1;
    };
    void push(int n){
        printf("PUSH %d\n",n);
        if(size==capacity){
            capacity*=2;
            int *temp = (int*)malloc(sizeof(int)*capacity);
            for(int i = 1; i < size; i++)
                temp[i] = DATA[i];
            free(DATA);
            DATA = temp;
        }
        DATA[size++] = n;
        int cur = size-1;
        while(DATA[cur]>DATA[cur/2]&&(cur/2)!=0){
            SWAP(&DATA[cur],&DATA[cur/2]);
            cur /= 2;
        }
    }
    int pop(){
        if(size==1){
            printf("IS EMPTY\n");
            return -1;
        }
        int ret = DATA[1];
        DATA[1] = DATA[--size];
        int cur = 1, left = 2, right = 3;
        while(cur<size){
            int next = cur;
            if(left<size&&DATA[cur]<DATA[left]) next = left;
            if(right<size&&DATA[cur]<DATA[right]&&DATA[right]>DATA[left]) next = right;
            if(next==cur) break;
            SWAP(&DATA[cur],&DATA[next]);
            cur = next;
            left = cur*2;
            right = left+1;
        }
        return ret;
    }
};
int main(int argc, char** argv){
    Priority_Queue pq;
    for(int i = 1; i<=10;i++)
        pq.push(i);
    for(int i = 1; i <= 10; i++)
        printf("POP : %d\n",pq.pop());
}