C29 Answer

#include <stdio.h>
#include <stdlib.h>

/* Puzzle C29 -- delete the element at index N,
|  move elements down to fill the gap.
|
|  Do nothing to the array if index N does not exist,
|  and return 0. Otherwise return 1.
|
*/
int deleteElement( int arr[], int size, int n )
{
  int j;
  
  if ( !(0<=n && n<size) ) return 0;
  
  for ( j=n; j < size-1; j++ )
    arr[j] = arr[j+1];
    
  arr[size-1] = 0;
  
  return 1;
}

void printArray( int arr[], int size )
{
  const int N = 10;
  int j;
  
  for ( j=0; j < size; j++ )
  {
    if ( j%N == N-1 )
      printf("%4d\n", arr[j] );
    else
      printf("%4d ", arr[j] );    
  }
}

void fillArrayInOrder( int arr[], int size, int first )
{
  int j;

  for ( j=0; j < size; j++ )
  {
    arr[j] = first+j;
  }
}

int main(int argc, char *argv[])
{
  const int SIZE =  25;
  int x[SIZE];
  char input[32];
  int del ;

  fillArrayInOrder( x, SIZE, 0 );
  printArray( x, SIZE );
  
  printf("\ndelete at index:");
  gets( input );
  while ( strcmp( input, "q") != 0 )
  {
    del = atoi( input );
    if ( deleteElement( x, SIZE, del ) )
      printf("Success\n\n");
    else
      printf("Failure\n\n");
    printArray( x, SIZE );
    printf("\ndelete at index:");
    gets( input );
  }
  
  system("pause");	
  return 0;
}