/in/shortestP2P.cc: In member function 'void ShortestP2P::readGraph()':
/in/shortestP2P.cc:48:18: error: 'arr' was not declared in this scope
               if(arr[i][j]<0 && (i==j))
                  ^~~
/in/shortestP2P.cc:48:18: note: suggested alternative: 'array'
               if(arr[i][j]<0 && (i==j))
                  ^~~
                  array