Compilare: main.cpp: In function 'int main()': main.cpp:52:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("gfact.in","r",stdin) ; ^ main.cpp:53:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("gfact.out","w",stdout) ; ^ main.cpp:54:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &p, &q) ; ^