added example 2.10_23

2.10_23.pl

+% nacteni:
+/* ['2.10_23.pl']. */
+
+stree(Graph,Tree) :- member(Edge,Graph),spread([Edge],Tree,Graph).
+spread(Tree1,Tree,Graph) :- addedge(Tree1,Tree2,Graph),spread(Tree2,Tree,Graph).
+spread(Tree,Tree,Graph) :- \+ addedge(Tree,_,Graph).
+addedge(Tree,[A-B|Tree],Graph) :- adjacent(A,B,Graph),node(A,Tree), \+ node(B,Tree).
+adjacent(A,B,Graph) :- member(A-B,Graph);member(B-A,Graph).
+node(A,Graph) :- adjacent(A,_,Graph), !. % bez rezu cil uspeje az deg(G)-krat, coz nam potom generuje identicke kostry.
+
+% demonstracni vypis
+
+  % abychom se vyhli varovanim "Redefined static procedure ..."
+:- dynamic
+       write_all_X/3,
+       start/0.
+
+write_all_X(Goal,X,Name):-
+            call(Goal),write('  '),write(Name),write(' = '),write(X),nl,fail.
+write_all_X(_,_,_).
+
+start:- 
+    write('Kostra grafu'),nl,
+    write('Volani "stree([a-b,b-c,b-d,c-d],T)" vrati:'),nl,
+    write_all_X(stree([a-b,b-c,b-d,c-d],T), T, 'T').
+
+?-start.
+
+:- retractall(write_all_X/3).
+:- retractall(start/0).

2.10_23.py

+#!/usr/bin/env python
+# encoding=utf-8 (pep 0263)
+
+from linked_lists import LinkedList, Cons, Nil
+
+def stree(graph):
+    for edge in member_anyX(graph):
+        for kostra in spread(LinkedList(edge), graph):
+            yield kostra
+
+def spread(akumulator_kostry, graph):
+    for akumulator_kostry1 in addedge(akumulator_kostry, graph):
+        for kostra in spread(akumulator_kostry1, graph):
+            yield kostra
+    try:
+        next(addedge(akumulator_kostry, graph))
+    except StopIteration: # nelze pridat hranu
+        yield akumulator_kostry
+
+def addedge(akumulator_kostry, graph):
+    for x, y in adjacent_anyXY(graph):
+        if node(x, akumulator_kostry) and not node(y, akumulator_kostry):
+            yield Cons((x, y), akumulator_kostry)
+
+def adjacent_anyY(x, edges):
+    for a, b in member_anyX(edges):
+        if x == a:
+            yield b
+        if x == b:
+            yield a
+
+def adjacent_anyXY(edges):
+    for a, b in member_anyX(edges):
+        yield (a, b)
+        yield (b, a)
+
+def node(x, graph):
+    try:
+        next(adjacent_anyY(x, graph))
+        return True
+    except StopIteration:
+        return False
+
+def member(x, xs):
+    if xs == Nil:
+        return False
+    if x == xs.head:
+        return True
+    return member(x, xs.tail)
+
+def member_anyX(xs):
+    if xs == Nil:
+        return
+    yield xs.head
+    for x in member_anyX(xs.tail):
+        yield x
+
+# demonstracni vypis
+if __name__ == "__main__":
+    print('Kostra grafu')
+    print('Volani stree(LinkedList(("a", "b"), ("b", "c"), ("b", "d"), ("c", "d"))) vrati:')
+    for kostra_ in stree(LinkedList(("a", "b"), ("b", "c"), ("b", "d"), ("c", "d"))):
+        print('  %s' % kostra_)

2.10_23.py.out

+Kostra grafu
+Volani stree(LinkedList(("a", "b"), ("b", "c"), ("b", "d"), ("c", "d"))) vrati:
+  [('b', 'd'), ('b', 'c'), ('a', 'b')]
+  [('c', 'd'), ('b', 'c'), ('a', 'b')]
+  [('b', 'c'), ('b', 'd'), ('a', 'b')]
+  [('d', 'c'), ('b', 'd'), ('a', 'b')]
+  [('b', 'd'), ('b', 'a'), ('b', 'c')]
+  [('c', 'd'), ('b', 'a'), ('b', 'c')]
+  [('b', 'a'), ('b', 'd'), ('b', 'c')]
+  [('b', 'a'), ('c', 'd'), ('b', 'c')]
+  [('b', 'c'), ('b', 'a'), ('b', 'd')]
+  [('d', 'c'), ('b', 'a'), ('b', 'd')]
+  [('b', 'a'), ('b', 'c'), ('b', 'd')]
+  [('b', 'a'), ('d', 'c'), ('b', 'd')]
+  [('b', 'a'), ('c', 'b'), ('c', 'd')]
+  [('b', 'a'), ('d', 'b'), ('c', 'd')]

Makefile

@@ -40,6 +40,7 @@ pylint2:
 	# pylint2 test
 	@if ! REPORT="$$(pylint $(PYLINT2_OPTIONS) *.py 2>&1)"; then \
 		printf "%s\n" "$$REPORT"; \
+		exit 1; \
 	fi
 	# pylint2 test ok
 
@@ -47,5 +48,6 @@ pylint3:
 	# pylint3 test
 	@if ! REPORT="$$(pylint3 $(PYLINT3_OPTIONS) *.py 2>&1)"; then \
 		printf "%s\n" "$$REPORT"; \
+		exit 1; \
 	fi
 	# pylint3 test ok