Seg is not a keyword, so it must be a custom variable name, p 1=seg[i], which means seg is an array or pointer, and p 1 is its element type. As for what type it is, it depends on the type used when defining seg variables in the program.

For example, define an integer array: int seg [10];

Or int * seg；; seg =(int *)malloc(sizeof(int)* 10)；