Compilare: user.cpp: In function ‘void FirstCase()’: user.cpp:20:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<strlen(chr)-1; i++) ^ user.cpp:32:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i==strlen(chr)-2) ^ user.cpp: In function ‘void SecondCase()’: user.cpp:51:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=1; i<strlen(chr)-1; i++) ^ user.cpp:59:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i==strlen(chr)-2) ^ user.cpp: In function ‘void Read()’: user.cpp:72:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n",&first); ^ user.cpp:73:14: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(chr); ^ user.cpp: In function ‘int main()’: user.cpp:85:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("charlie.in","r",stdin); ^ /tmp/ccUTACgE.o: In function `Read()': user.cpp:(.text+0x287): warning: the `gets' function is dangerous and should not be used.