Compilare: user.cpp: In function ‘void calc()’: user.cpp:22:9: warning: unused variable ‘i’ [-Wunused-variable] int i; ^ user.cpp: In function ‘int main()’: user.cpp:55:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("marvel.in", "r", stdin); ^ user.cpp:56:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("marvel.out", "w", stdout); ^ user.cpp:61:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &v[i]); ^ user.cpp:63:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &ele[i]); ^ user.cpp:67:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &a, &b); ^