Eroare de compilare: user.c: In function ‘Sieve’: user.c:15: error: ‘for’ loop initial declarations are only allowed in C99 mode user.c:15: note: use option -std=c99 or -std=gnu99 to compile your code user.c:18: error: redefinition of ‘i’ user.c:15: note: previous definition of ‘i’ was here user.c:18: error: ‘for’ loop initial declarations are only allowed in C99 mode user.c:19: error: ‘for’ loop initial declarations are only allowed in C99 mode user.c:22: error: redefinition of ‘i’ user.c:18: note: previous definition of ‘i’ was here user.c:22: error: ‘for’ loop initial declarations are only allowed in C99 mode user.c: At top level: user.c:28: warning: return type of ‘main’ is not ‘int’ user.c: In function ‘main’: user.c:30: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c:31: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c:33: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result