prepare (1/3): 
finished

make (2/3): 
g++ -g -Wall -O2 -o main.o -c main.cpp 
In file included from main.cpp:2:0:
class.h: In member function 'void Prim_manager::update_weight(int)':
class.h:101:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<v->edgenum;i++){
                 ~^~~~~~~~~~~
class.h: In member function 'bool Prim_manager::all_connected()':
class.h:112:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<numvertex;i++){
                 ~^~~~~~~~~~
class.h: In member function 'int Prim_manager::next_to_connect()':
class.h:122:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<numvertex;i++){
                 ~^~~~~~~~~~
class.h: In member function 'int Prim_manager::find_connector(int)':
class.h:140:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<v->edgenum;i++){
                 ~^~~~~~~~~~~
class.h: In member function 'void Prim_manager::connect(int, int)':
class.h:156:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=1;i<v1->edgenum;i++){
                 ~^~~~~~~~~~~~
class.h:162:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=1;i<v2->edgenum;i++){
                 ~^~~~~~~~~~~~
class.h: In destructor 'Prim_manager::~Prim_manager()':
class.h:185:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<vertixlist.size();i++){
                 ~^~~~~~~~~~~~~~~~~~
class.h:186:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int j=0;j<vertixlist[i]->edgelist.size();j++){
                     ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
main.cpp: In function 'int main()':
main.cpp:10:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<numedge;i++){
                 ~^~~~~~~~
In file included from main.cpp:2:0:
class.h: In member function 'int Prim_manager::next_to_connect()':
class.h:130:12: warning: 'minvertix' may be used uninitialized in this function [-Wmaybe-uninitialized]
     return minvertix;
            ^~~~~~~~~
main.cpp: In function 'int main()':
main.cpp:22:20: warning: 'minvertix' may be used uninitialized in this function [-Wmaybe-uninitialized]
         pm->connect(a,b);
         ~~~~~~~~~~~^~~~~
g++ -g -Wall -O2 -o main main.o
finished

clean (3/3): 
finished

all task finished, build successfully