Compilare: main.c: In function 'main': main.c:11:13: warning: format '%d' expects argument of type 'int *', but argument 2 has type 'int' [-Wformat=] scanf("%d", n); ^ main.c:15:15: warning: too many arguments for format [-Wformat-extra-args] scanf("%d", &a, &b); ^~~~ main.c:16:22: warning: implicit declaration of function 'gcd' [-Wimplicit-function-declaration] printf("%d", gcd(a,b)); ^~~ main.c:8:5: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("euclid2.in", "r", stdin); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:9:5: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("euclid2.out", "w", stdout); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:11:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", n); ^~~~~~~~~~~~~~ main.c:15:9: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a, &b); ^~~~~~~~~~~~~~~~~~~ main.c:11:5: warning: 'n' is used uninitialized in this function [-Wuninitialized] scanf("%d", n); ^~~~~~~~~~~~~~