Compilare: user.cpp: In function ‘int add(int)’: user.cpp:53:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:78:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("collar.in", "r", stdin); ^ user.cpp:79:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("collar.out", "w", stdout); ^ user.cpp:81:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:83:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a[i]); ^