Geekers Point

Allocate a dynamic array of a  stated size.Load numbers into the array and then sum the numbers in the array.

  
#include <stdio.h>

#include <stdlib.h>


int main()
{
int retval;   /* value returned from scanf */
long *nums;   /* pointer to arrray of numbers to sum */
short how_many;/* number of numbers to input and sum */
short inum;   /* counter to index into nums array */
long sum;     /* sum of numbers in nums array */
    /*
    *    input number of elements to allocate
    */
    printf("\nHow many numbers to sum? ");
    scanf("%hd",&how_many);
    /*
    *    dynamically allocate memory for how_manay 
    *    long's
    */
 nums = (long *)calloc(how_many, sizeof(long) );

    if(nums == (long *)NULL)
    {
         fprintf(stderr,"\nCould not allocate memory");
         return 1;
    }
    /*
    *    input numbers to store in array
    */
    for( inum =0; inum < how_many; ++inum)
    {
         printf("\nEnter #%d: ", inum + 1);
         retval = scanf("%ld",&nums[inum] );
    }
    /*
    *    sum the numbers in the array
    */
    for( sum = inum = 0; inum < how_many; ++inum )
    {
         /*
         *    add number to sum
         */
         sum += nums[inum];
         /*
         *    show running total
         */
         printf("\n%3d: %10ld %10ld",
              inum+1,nums[inum],sum);
    }
    /*
    *    print the final total
    */
    printf("\nThe sum of the %d numbers",how_many);
    printf(" entered is %ld\n",sum);
    /*
    *    free the memory back to the heap
    */
    free( (char *)nums );
    return 0;

}

Executing the program....
$demo

How many numbers to sum? 
Enter #1: 
Enter #2: 
  1:         21         21
  2:          3         24
The sum of the 2 numbers entered is 24

// C program to delete N nodes after M nodes of a linked list #include <stdio.h> #include <stdlib.h> // A linked list node struct node {     int data;     struct node *next; }; /* Function to insert a node at the beginning */ void push(struct node ** head_ref, int new_data) {     /* allocate node */     struct node* new_node = (struct node*) malloc(sizeof(struct node));     /* put in the data  */     new_node->data  = new_data;     /* link the old list off the new node */     new_node->next = (*head_ref);     /* move the head to point to the new node */     (*head_ref)  = new_node; } /* Function to print linked list */ void printList(struct node *head) {     struct node *temp = head;     while (temp != NULL)     {         printf("%d ", temp->data);         temp = temp->next;     }     printf("\n"); } // Function to skip M nodes and then delete N nodes of the linked list. void skipMdeleteN(struct node  *head, int M, int N) {     struct node *curr = head, *t;     int count;     // The main loop that traverses through the whole list     while (curr)     {         // Skip M nodes         for (count = 1; count<M && curr!= NULL; count++)             curr = curr->next;         // If we reached end of list, then return         if (curr == NULL)             return;         // Start from next node and delete N nodes         t = curr->next;         for (count = 1; count<=N && t!= NULL; count++)         {             struct node *temp = t;             t = t->next;             free(temp);         }         curr->next = t; // Link the previous list with remaining nodes         // Set current pointer for next iteration         curr = t;     } } // Driver program to test above functions int main() {     /* Create following linked list       1->2->3->4->5->6->7->8->9->10 */     struct node* head = NULL;     int M=2, N=3;     push(&head, 10);     push(&head, 9);     push(&head, 8);     push(&head, 7);     push(&head, 6);     push(&head, 5);     push(&head, 4);     push(&head, 3);     push(&head, 2);     push(&head, 1);     printf("M = %d, N = %d \nGiven Linked list is :\n", M, N);     printList(head);     skipMdeleteN(head, M, N);     printf("\nLinked list after deletion is :\n");     printList(head);     return 0; }