Compilare: user.cpp: In function ‘int main()’: user.cpp:28:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<s.length(); ++i) ^ user.cpp:31:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<(curr.length()>>1); ++i) ^ user.cpp:36:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<v.size(); ++i) ^ user.cpp:37:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=i+1; j<v.size(); ++j) ^ user.cpp:41:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int a=0; a<v[i].length(); ++a) ^ user.cpp:42:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int b=0; b<v[j].length(); ++b) ^ user.cpp:39:17: warning: unused variable ‘curr’ [-Wunused-variable] int curr = 0; ^