Compilare: user.cpp: In function ‘int main()’: user.cpp:55:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<s.size()-1;++i) printf("%d\n",s[i]); ^ user.cpp:42:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("nc.in","r",stdin); ^ user.cpp:43:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("nc.out","w",stdout); ^ user.cpp:45:13: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(tx);ind=0;Z=strlen(tx); ^ user.cpp: In function ‘void solve()’: user.cpp:28:22: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(tx);ind=0; ^ user.cpp:35:50: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] if(ind==Z) Z=strlen(tx) ,ind=0, gets(tx); ^ /tmp/ccaUjmvR.o: In function `main': user.cpp:(.text.startup+0x56): warning: the `gets' function is dangerous and should not be used.