Compilare: user.cpp: In function ‘int main()’: user.cpp:68:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int s = 0; s<L[1].size(); s++) { ^ user.cpp:71:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<L[2].size(); i++) ^ user.cpp:75:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0; j<L[i].size(); j++) { ^ user.cpp:78:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (k=0; k<L[i-1].size(); k++) { ^ user.cpp:83:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<L[n].size(); i++) ^