Compilare: user.cpp: In function ‘int main()’: user.cpp:14:24: warning: format ‘%c’ expects argument of type ‘char*’, but argument 2 has type ‘int*’ [-Wformat=] scanf("%c", &ch); ^ user.cpp:9:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("compress.in", "r", stdin); ^ user.cpp:10:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("compress.out", "w", stdout); ^ user.cpp:14:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%c", &ch); ^