Compilare: user.cpp: In function ‘int Found(int, int)’: user.cpp:20:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<fr1[lin].size();i++) ^ user.cpp: In function ‘void Solve()’: user.cpp:39:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<fr[i].size();j++) ^ user.cpp:40:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(k=j+1;k<fr[i].size();k++) ^