P-> PRIOR points to Q, and Q is the precursor node of P; P-> prior->next is equal to Q-> next, P-> prior->next is equal to the post-drive pointer field of Q

The scanf() function reads the value from the input stream buffer and ends with a carriage return (\n). Scanf (” %c”) with a space means that two characters are to be read from the input stream buffer, one for space and one for %c. The reason for the space is that the carriage return (\n) is also in the input stream buffer, so \n is assigned to the space so that %c is correctly assigned. Otherwise, without Spaces, the carriage return \n will be assigned to %c. So without Spaces, character input will be problematic.

The * symbol has two meanings. 1. It acts as a “pointer specifier” when the pointer is not assigned or initialized. 2. After a pointer has already pointed to it, it is used as a fetcher.

The definition of a pointer takes two forms:

  1. int a=101;

    int *p;



int a=101;

int p=&a;