triunghi.cpp: In function 'int main()': triunghi.cpp:76: warning: comparison between signed and unsigned integer expressions triunghi.cpp:49: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result triunghi.cpp:50: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result triunghi.cpp:52: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result triunghi.cpp:54: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result triunghi.cpp:63: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result