timer.cpp: In function 'int main()': timer.cpp:24: warning: comparison between signed and unsigned integer expressions timer.cpp:31: warning: comparison between signed and unsigned integer expressions timer.cpp:38: warning: comparison between signed and unsigned integer expressions timer.cpp:52: warning: comparison between signed and unsigned integer expressions timer.cpp:59: warning: comparison between signed and unsigned integer expressions timer.cpp:66: warning: comparison between signed and unsigned integer expressions timer.cpp:74: warning: comparison between signed and unsigned integer expressions timer.cpp:81: warning: comparison between signed and unsigned integer expressions timer.cpp:89: warning: comparison between signed and unsigned integer expressions timer.cpp:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result timer.cpp:18: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result timer.cpp:21: warning: ignoring return value of 'char* gets(char*)', declared with attribute warn_unused_result timer.cpp:22: warning: ignoring return value of 'char* gets(char*)', declared with attribute warn_unused_result timer.cpp:23: warning: ignoring return value of 'char* gets(char*)', declared with attribute warn_unused_result /tmp/ccJNgo8j.o: In function `main': timer.cpp:(.text+0x86): warning: the `gets' function is dangerous and should not be used.