Compilare: user.cpp: In function ‘void friends()’: user.cpp:40:12: warning: unused variable ‘p’ [-Wunused-variable] int i, p; ^ user.cpp: In function ‘void solve()’: user.cpp:49:9: warning: unused variable ‘i’ [-Wunused-variable] int i; ^ user.cpp: In function ‘void read()’: user.cpp:9:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("copaci4.in", "r", stdin); ^ user.cpp:10:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:13:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &v[i]); ^ user.cpp: In function ‘void write()’: user.cpp:56:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("copaci4.out", "w", stdout); ^