powerpuff.cpp: In function 'int main()': powerpuff.cpp:18: warning: comparison between signed and unsigned integer expressions powerpuff.cpp:19: warning: array subscript has type 'char' powerpuff.cpp:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result powerpuff.cpp:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result powerpuff.cpp:13: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result powerpuff.cpp:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result powerpuff.cpp:17: warning: ignoring return value of 'char* gets(char*)', declared with attribute warn_unused_result /tmp/cckTbqsm.o: In function `main': powerpuff.cpp:(.text+0xb2): warning: the `gets' function is dangerous and should not be used.