Compilare: user.cpp: In function ‘void df_1(int, int)’: user.cpp:14:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < L[in].size(); i ++) ^ user.cpp: In function ‘void dijkstra(int, int)’: user.cpp:33:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < L[in].size(); i ++) ^ user.cpp:75:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < L[act].size(); i ++) { ^ user.cpp: In function ‘int main()’: user.cpp:116:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0; j < L[A].size(); j ++) { ^