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 nr_pos(int, int)’: user.cpp:45: warning: array subscript has type ‘char’ user.cpp: In function ‘long long int count_matrix(int)’: user.cpp:56: warning: comparison between signed and unsigned integer expressions user.cpp:54: warning: unused variable ‘j’ user.cpp: In function ‘void back(int)’: user.cpp:62: warning: comparison between signed and unsigned integer expressions user.cpp:74: warning: array subscript has type ‘char’ user.cpp: In function ‘int main()’: user.cpp:102: warning: unused variable ‘m’ user.cpp:99: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:100: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result