Compilare: user.cpp: In function ‘void perm(char*)’: user.cpp:10:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<strlen(s)-1;i++) ^ user.cpp: In function ‘bool palindrom(char*)’: user.cpp:17:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<strlen(s)/2;i++) ^ user.cpp:16:11: warning: unused variable ‘n’ [-Wunused-variable] int i,n=strlen(s); ^ user.cpp: In function ‘int main()’: user.cpp:26:9: warning: unused variable ‘x’ [-Wunused-variable] int x,cnt=0; ^ user.cpp:24:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("palc.in","r",stdin); ^ user.cpp:25:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("palc.out","w",stdout); ^ user.cpp:27:12: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s); ^ /tmp/ccvwoid2.o: In function `main': user.cpp:(.text.startup+0x5a): warning: the `gets' function is dangerous and should not be used.