prog.c: In function ‘main’:
prog.c:10:2: warning: implicit declaration of function ‘scanf_s’; did you mean ‘scanf’? [-Wimplicit-function-declaration]
scanf_s("%d", &year);
^~~~~~~
scanf
prog.c:12:2: error: unknown type name ‘bool’; did you mean ‘_Bool’?
bool rst = ((year % 4 == 0) && (year % 100 != 0)) || (year % 400 == 0);
^~~~
_Bool
prog.c:7:6: warning: unused variable ‘yun’ [-Wunused-variable]
int yun;
^~~