Question

so far, i m working on the array with 0th location but m in need to change it from 0 to 1 such that if earlier it started for 0 to n-1 then now it should start form 1 to n. is there any way out to resolve this problem?

Answer 1

Subtract 1 from the index every time you access the array to achieve “fake 1-based” indexing.

If you want to change the numbering while the program is running, you’re asking for something more than just a regular array. If things only ever shift by one position, then allocate (n+1) slots and use a pointer into the array.

enum { array_size = 1000 };

int padded_array[ array_size + 1 ];
int *shiftable_array = padded_array; /* define pointer */

shiftable_array[3] = 5; /* pointer can be used as array */
some_function( shiftable_array );

/* now we want to renumber so element 1 is the new element 0 */
++ shiftable_array; /* accomplished by altering the pointer */

some_function( shiftable_array ); /* function uses new numbering */

If the shift-by-one operation is repeated indefinitely, you might need to implement a circular buffer.