Compilare: user.cpp: In function ‘void read()’: user.cpp:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:25: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result user.cpp: In function ‘int count_matrix(int)’: user.cpp:40: warning: comparison between signed and unsigned integer expressions user.cpp:48: warning: array subscript has type ‘char’ user.cpp: In function ‘void back(int)’: user.cpp:60: warning: comparison between signed and unsigned integer expressions user.cpp:72: warning: array subscript has type ‘char’ user.cpp: In function ‘int main()’: user.cpp:83: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:84: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result