Compilare: user.c: In function ‘read_students’: user.c:16: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c:17: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c:25: warning: ignoring return value of ‘fgets’, declared with attribute warn_unused_result user.c: In function ‘print_students’: user.c:33: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c: In function ‘sort_students’: user.c:45: warning: implicit declaration of function ‘strcmp’ user.c:46: warning: implicit declaration of function ‘strcpy’ user.c:46: warning: incompatible implicit declaration of built-in function ‘strcpy’ user.c:46: warning: passing argument 1 of ‘strcpy’ from incompatible pointer type user.c:46: note: expected ‘char *’ but argument is of type ‘char **’ user.c:48: warning: passing argument 2 of ‘strcpy’ from incompatible pointer type user.c:48: note: expected ‘const char *’ but argument is of type ‘char **’ user.c: In function ‘main’: user.c:58: warning: passing argument 1 of ‘read_students’ from incompatible pointer type user.c:12: note: expected ‘struct student *’ but argument is of type ‘struct student (*)[10000000]’ user.c:59: warning: passing argument 1 of ‘sort_students’ from incompatible pointer type user.c:38: note: expected ‘struct student *’ but argument is of type ‘struct student (*)[10000000]’ user.c:60: warning: passing argument 1 of ‘print_students’ from incompatible pointer type user.c:30: note: expected ‘struct student *’ but argument is of type ‘struct student (*)[10000000]’