Compilare: user.cpp: In function ‘int main()’: user.cpp:55:12: warning: unused variable ‘sum’ [-Wunused-variable] int n, sum = 0, x; ^ user.cpp:55:21: warning: unused variable ‘x’ [-Wunused-variable] int n, sum = 0, x; ^ user.cpp:52:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(FILEIN, "r", stdin); ^ user.cpp:53:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(FILEOUT, "w", stdout); ^ user.cpp:76:43: warning: ‘stop’ may be used uninitialized in this function [-Wmaybe-uninitialized] cout << sol << ' ' << start << ' ' << stop << '\n'; ^ user.cpp:76:27: warning: ‘start’ may be used uninitialized in this function [-Wmaybe-uninitialized] cout << sol << ' ' << start << ' ' << stop << '\n'; ^