Compilare: user.cpp: In function ‘void read_matrix(const char*)’: user.cpp:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:42: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘void solve(char*)’: user.cpp:57: warning: unused variable ‘st’ user.cpp:59: warning: unused variable ‘stop’ user.cpp:60: warning: unused variable ‘start’ user.cpp:67: warning: unused variable ‘Sol’ user.cpp:110: warning: unused variable ‘end’ user.cpp: In function ‘int main(int, char**)’: user.cpp:124: warning: deprecated conversion from string constant to ‘char*’ user.cpp:123: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result