trmv.cpp: In function 'int main()': trmv.cpp:38: warning: comparison between signed and unsigned integer expressions trmv.cpp:17: warning: unused variable 'n1' trmv.cpp:17: warning: unused variable 'n2' trmv.cpp:15: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result trmv.cpp:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result trmv.cpp:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result trmv.cpp:21: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result trmv.cpp:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result trmv.cpp:45: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result