Data commit

Task/Tarjan/11l/tarjan.11l

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+T Graph
+   String name
+   [Char = [Char]] graph
+   Int _order
+   [Char = Int] disc
+   [Char = Int] low
+   [Char] stack
+   [[Char]] scc
+
+   F (name, connections)
+      .name = name
+
+      DefaultDict[Char, [Char]] g
+      L(n) connections
+         V (n1, n2) = (n[0], n[1])
+         I n1 != n2
+            g[n1].append(n2)
+         E
+            g[n1]
+         g[n2]
+
+      .graph = Dict(move(g))
+      .tarjan_algo()
+
+   F _visitor(this) -> N
+      ‘
+        Recursive function that finds SCC's
+        using DFS traversal of vertices.
+
+        Arguments:
+            this        --> Vertex to be visited in this call.
+            disc{}      --> Discovery order of visited vertices.
+            low{}       --> Connected vertex of earliest discovery order
+            stack       --> Ancestor node stack during DFS.
+      ’
+      .disc[this] = .low[this] = ._order
+      ._order++
+      .stack.append(this)
+
+      L(neighbr) .graph[this]
+         I neighbr !C .disc
+            ._visitor(neighbr)
+            .low[this] = min(.low[this], .low[neighbr])
+
+         E I neighbr C .stack
+            .low[this] = min(.low[this], .disc[neighbr])
+
+      I .low[this] == .disc[this]
+         [Char] new
+         L
+            V top = .stack.pop()
+            new.append(top)
+            I top == this
+               L.break
+         .scc.append(new)
+
+   F tarjan_algo()
+      ‘
+        Recursive function that finds strongly connected components
+        using the Tarjan Algorithm and function _visitor() to visit nodes.
+      ’
+      ._order = 0
+
+      L(vertex) sorted(.graph.keys())
+         I vertex !C .disc
+            ._visitor(vertex)
+
+L(n, m) [(‘Tx1’, ‘10 02 21 03 34’.split(‘ ’)),
+         (‘Tx2’, ‘01 12 23’.split(‘ ’)),
+         (‘Tx3’, ‘01 12 20 13 14 16 35 45’.split(‘ ’)),
+         (‘Tx4’, ‘01 03 12 14 20 26 32 45 46 56 57 58 59 64 79 89 98 AA’.split(‘ ’)),
+         (‘Tx5’, ‘01 12 23 24 30 42’.split(‘ ’))
+         ]
+   print("\n\nGraph('#.', #.):\n".format(n, m))
+   V g = Graph(n, m)
+   print(‘               :  ’sorted(g.disc.keys()).map(v -> String(v)).join(‘  ’))
+   print(‘    DISC of ’(g.name‘:’)‘ ’sorted(g.disc.items()).map((_, v) -> v))
+   print(‘     LOW of ’(g.name‘:’)‘ ’sorted(g.low.items()).map((_, v) -> v))
+   V scc = (I !g.scc.empty {String(g.scc).replace(‘'’, ‘’).replace(‘,’, ‘’)[1 .< (len)-1]} E ‘’)
+   print("\n   SCC's of "(g.name‘:’)‘ ’scc)