cifre.cpp: In function 'int main()': cifre.cpp:14: warning: comparison between signed and unsigned integer expressions cifre.cpp:8: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result cifre.cpp:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result cifre.cpp:12: warning: ignoring return value of 'char* gets(char*)', declared with attribute warn_unused_result cifre.cpp:16: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result /tmp/ccNLfj1k.o: In function `main': cifre.cpp:(.text+0x56): warning: the `gets' function is dangerous and should not be used.