Compilare: main.cpp: In function 'int main()': main.cpp:30:45: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ( "procente.in" , "r" , stdin ) ; ^ main.cpp:31:47: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ( "procente.out" , "w" , stdout ) ; ^ main.cpp:36:45: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d\n%c%d" , & n , & ch , & x ) ; ^