Compilare: user.cpp: In function ‘int main()’: user.cpp:45:12: warning: unused variable ‘j’ [-Wunused-variable] int i, j, k, ok, x; ^ user.cpp:45:15: warning: unused variable ‘k’ [-Wunused-variable] int i, j, k, ok, x; ^ user.cpp:45:18: warning: unused variable ‘ok’ [-Wunused-variable] int i, j, k, ok, x; ^ user.cpp:48:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(inputFile.c_str(), "r", stdin); ^ user.cpp:49:45: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(outputFile.c_str(), "w", stdout); ^ user.cpp:52:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &N); ^ user.cpp:55:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^