tabla.cpp: In function 'int main()': tabla.cpp:66: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result tabla.cpp:67: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result tabla.cpp:68: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result tabla.cpp:71: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result