Compilare: user.cpp: In function ‘int main()’: user.cpp:20:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<str.size();++i)s.push_back(str[i]); ^ user.cpp:32:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(v[j].size()<=i){ ^ user.cpp:33:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(mat[i-1][j]+2*v[j].size()-1<=i || mat[i-1][j]==-1){ ^ user.cpp:59:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(v[j].size()<=i){ ^