why am i getting this error ? my program is in C

.. L.30.29! error: use of undeclared identifier 'new' struct Graph* graph = new Graph; testing.c:30:32: error: expected ';' at end of declaration struct Graph* graph = new Graph; testing.c:34:21: error: use of undeclared identifier 'new' graph->edge = new Edge[E]; 3 errors generated