Manually Memory Allocation By using MALLOC in C

Manually Memory Allocation By using MALLOC in C

#include 
#include 
main()
{
int  *base; 
int i;  
int cnt=0;
int sum=0;
printf("how many integers you have to store \n"); 
scanf("%d",&cnt); 
base = (int *)malloc(cnt * sizeof(int));
printf("the base of allocation is %16lu \n",base);
if(!base)
  printf("unable to allocate size \n");
else
 {  
 for(int j=0;j<=cnt;j++) 
 *(base+j)=5;
 }
 sum = 0;
 for(int j=0;j<=cnt;j++)  
 sum = sum + *(base+j);
 printf("total sum is %d\n",sum);
 free(base); 
 printf("the base of allocation is %16lu \n",base);
 base = (int *)malloc(cnt * sizeof(int));
printf("the base of allocation is %16lu \n",base);
 base = (int *)malloc(cnt * sizeof(int)); 
printf("the base of allocation is %16lu \n",base);
 base = (int *)calloc(10,2);   
printf("the base of allocation is %16lu \n",base);


}