prepare (1/3): 
finished

make (2/3): 
g++ -g -Wall -I. -O2 -std=c++11  -o main.o -c main.cpp
In file included from main.cpp:6:0:
graph.h: In constructor 'Graph::Graph(int&)':
graph.h:87:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for ( int i = 0; i < nodeNumbers; i++){
                      ~~^~~~~~~~~~~~~
graph.h: In member function 'void Graph::topologicalSort()':
graph.h:156:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int i = 0; i < nodeNumbers; i++){
                         ~~^~~~~~~~~~~~~
g++ -g -Wall -I. -O2 -std=c++11  -o main main.o
finished

clean (3/3): 
finished

all task finished, build successfully