Compilare: user.cpp: In function ‘void build()’: user.cpp:38:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=2; i<s.length(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:8:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] #define min(a,b) ((a<b)?a:b) ^ user.cpp:88:21: note: in expansion of macro ‘min’ for (int i=0; i<min(sol.size(),1000); i++) ^