Compilare: main.cpp: In function 'void bellmanford(int)': main.cpp:31:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<graf[x].size();i++) ~^~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:60:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k=0;k<graf[a].size();k++) ~^~~~~~~~~~~~~~~ main.cpp:62:17: warning: unused variable 'b' [-Wunused-variable] int b=graf[a][k].first; ^ main.cpp:63:17: warning: unused variable 'cost' [-Wunused-variable] int cost=graf[a][k].second; ^~~~