C言語による配列への要素の追加と削除

# include <stdio.h>
int main(void)
{
  int a[23] = {1, 5, 66, 8, 55, 9, 1, 32, 5, 65, 4, 8, 5, 15, 64, 156, 1564, 15, 1, 8, 9, 7, 215};
  int b[24]; // the new array after inserting the number, because another value is inserted, so the length is 24
  int Index; // the subscript of the inserted value, Index is the English word for "subscript"
  int num; // the inserted value
  int i; //loop variable
  printf("Please enter the subscript of the inserted value: ");
  scanf("%d", &Index);
  printf("Please enter the inserted value: ");
  scanf("%d", &num);
  for (i=0; i<24; ++i)
  {
    if (i < Index)
    {
      b[i] = a[i]; /* loop variable i is less than the inserted value position Index, the position of each element placed unchanged */
    }
    else if (i == Index)
    {  
      b[i] = num; //if i equals Index, assign the inserted value to the array b
    }
    else
    {
      b[i] = a[i-1]; /* Because a new element is inserted, the position of each element after the insertion position is shifted back by one */
    }
  }
  for (i=0; i<24; ++i)
  {
    printf("%d\x20", b[i]);
  }
  printf("\n");
  return 0;
}

# include <stdio.h>
int main(void)
{
  int a[23] = {1, 5, 66, 8, 55, 9, 1, 32, 5, 65, 4, 8, 5, 15, 64, 156, 1564, 15, 1, 8, 9, 7, 215};
  int b[22]; /* the new array to store the deleted numbers, because one value is deleted, so the length is 22*/
  int Index; //Subscript of the value to be deleted
  int i; // loop variable
  printf("Please enter the subscript of the value to be deleted: ");
  scanf("%d", &Index);
  for (i=0; i<23; ++i)
  {
    if (i < Index)
    {
      b[i] = a[i]; /* loop variable i is less than the inserted value position Index, each element stored in the position remains unchanged */
    }
    else
    {
      b[i] = a[i+1]; /* The elements after the deleted value are shifted forward by one, and the value to be deleted is directly overwritten*/
    }
  }
  for (i=0; i<22; ++i)
  {
    printf("%d\x20", b[i]); // \x20 means space
  }
  printf("\n");
  return 0;
}

#include <stdio.h>

int main()
{
 int a[10] = { 5, 9, 11, 16, 24, 34, 37, 49, 51, 61 };
 int i = 0,n=0,k=0;
 char get;
 
 for (i = 0; i < 10; i++)
  printf("%3d", a[i]);
 printf("\n");
 printf("Please enter the operation to be performed (insert 'I',delete 'D')\n");
 
 get = getchar();
 getchar();
 
 if (get=='D')
 {
  printf("Please enter the integer to delete: \n");
  n = getchar(); 
  getchar();
  n -= 48;
  for (i = 0; i < 10; i++)
  {
  if (a[i]==n)
  {
   for (; i < 10; i++)
   {
    a[i] = a[i + 1];
   }
   a[9] = 0;
   break;
  }
  }
 for (i = 0; i < 9; i++)
  printf("%3d", a[i]);
 printf("\n");
 }
 
 printf("Please enter the operation to be performed (insert 'I',delete 'D')\n");
 get = getchar();
 getchar();
 
 if (get='I')
 {
 printf("Please enter the integer to be inserted:\n");
 scanf_s("%d", &n); // note the trap, you can't use getchar(), because 13 is actually two characters, after the carriage return, n only absorbs '1', so you can only use scanf_s().
 for (i = 0; i < 10; i++)
 {
  if (a[i] < n&&n < a[i + 1])
  {
  k = i;
  for (i = 8; i > k; i--)
  {
   a[i + 1] = a[i];
  }
  a[k+1] = n;
  break;
  }
 }
 for (i = 0; i < 10; i++)
  printf("%3d", a[i]);
 }
 return 0;
}