Compilare: main.cpp: In function 'void dijktra(long long int)': main.cpp:59:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < l[nod].size(); i++) ~~^~~~~~~~~~~~~~~ main.cpp: In function 'void prim()': main.cpp:97:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < l2[1].size(); i++) ~~^~~~~~~~~~~~~~ main.cpp:121:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < l2[nod].size(); i++) ~~^~~~~~~~~~~~~~~~ main.cpp: At global scope: main.cpp:134:7: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type] main() ^