Compilare: user.cpp: In function ‘int main()’: user.cpp:16:9: warning: unused variable ‘j’ [-Wunused-variable] int i, j, a, b, poz; ^ user.cpp:19:26: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(fin, "r", stdin); ^ user.cpp:21:28: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(fout, "w", stdout); ^ user.cpp:23:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%c", &ch); ^ user.cpp:31:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%c", &ch); ^