Write a C++ program that implements the topological sorting algorithm based on the DFS algorithm. Your program should read an input file name and determine if the input graph is a DAG (= directed acyclic graph) or not. If the graph is not a DAG, your program has to stop without further processing. However, if its a DAG, your program should display the starting node(s), popping-off order, and topologically sorted list. In the problem, you can assume that the number of nodes in the input file is less than 100. Input file format: This is a sample input file called t1.txt.

nut mc foraat This ed ei. tt 01 1 2 Output: $ g++-o?ts.cpp Enter a filename: C:VVtmp\Itl.txt This is a DAG Start node (s) 0 Popping-off order: 21 0 Topological sort: 0->2 nut mc foraat This ed ei. tt 01 1 2 Output: $ g++-o?ts.cpp Enter a filename: C:VVtmp\Itl.txt This is a DAG Start node (s) 0 Popping-off order: 21 0 Topological sort: 0->2