Compilare: user.c: In function ‘main’: user.c:63:16: warning: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 2 has type ‘size_t {aka unsigned int}’ [-Wformat=] printf("%lu\n", n); ^ user.c:65:20: warning: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 2 has type ‘size_t {aka unsigned int}’ [-Wformat=] printf("%lu ", s[i]); ^ user.c:18:5: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("strmatch.in", "r", stdin); ^ user.c:19:5: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("strmatch.out", "w", stdout); ^