pod.cpp: In function 'int main()': pod.cpp:73: error: name lookup of 'i' changed for ISO 'for' scoping pod.cpp:73: note: (if you use '-fpermissive' G++ will accept your code) pod.cpp:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result pod.cpp:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result pod.cpp:35: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result pod.cpp:37: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result