1 files changed, 14 insertions, 0 deletions
diff --git a/prolog/problems/trees/deletebt_3/en.py b/prolog/problems/trees/deletebt_3/en.py
new file mode 100644
index 0000000..557efaa
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+++ b/prolog/problems/trees/deletebt_3/en.py
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+id = 137
+name = 'deleteBT/3'
+slug = 'delete an element from a binary tree'
+
+description = '''\
+<p><code>deleteBT(X, T, NewT)</code>: the binary tree <code>NewT</code> is obtained from <code>T</code> by deleting one occurence of the element <code>X</code>. If <code>X</code> is not a leaf node, the root of one of its subtrees is moved up. Your code should generate all valid solutions.</p>
+<pre>
+  ?- deleteBT(1, b(b(b(nil,4,nil),2,b(nil,6,nil)),1,b(nil,3,b(nil,5,nil))), T).
+    T = b(b(nil,4,b(nil,6,nil)),2,b(nil,3,b(nil,5,nil))) ;
+    T = b(b(b(nil,4,nil),6,nil),2,b(nil,3,b(nil,5,nil))) ;
+    T = b(b(b(nil,4,nil),2,b(nil,6,nil)),3,b(nil,5,nil)).
+</pre>'''
+
+hint = {}