Compilare: main.cpp: In function 'void prim()': main.cpp:71:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<edge>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 71 | for(i=0; i<G[start].size(); i++) | ~^~~~~~~~~~~~~~~~ main.cpp:92:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<edge>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 92 | for(int k=0;k<G[vf].size();k++) | ~^~~~~~~~~~~~~ main.cpp:68:19: warning: unused variable 'j' [-Wunused-variable] 68 | int start=1,i,j,vfmin,x,costmin; | ^ main.cpp:68:21: warning: unused variable 'vfmin' [-Wunused-variable] 68 | int start=1,i,j,vfmin,x,costmin; | ^~~~~ main.cpp:68:27: warning: unused variable 'x' [-Wunused-variable] 68 | int start=1,i,j,vfmin,x,costmin; | ^ main.cpp:68:29: warning: unused variable 'costmin' [-Wunused-variable] 68 | int start=1,i,j,vfmin,x,costmin; | ^~~~~~~