diff options
Diffstat (limited to 'prolog/problems/old_exams')
-rw-r--r-- | prolog/problems/old_exams/pascal_3/common.py | 16 | ||||
-rw-r--r-- | prolog/problems/old_exams/pascal_3/en.py | 26 |
2 files changed, 42 insertions, 0 deletions
diff --git a/prolog/problems/old_exams/pascal_3/common.py b/prolog/problems/old_exams/pascal_3/common.py new file mode 100644 index 0000000..7fcb55e --- /dev/null +++ b/prolog/problems/old_exams/pascal_3/common.py @@ -0,0 +1,16 @@ +id = 179 +group = 'old_exams' +number = 86 +visible = False +facts = None + +solution = '''\ +pascal(_, 0, 1) :- !. +pascal(I, I, 1) :- !. +pascal(I, J, N) :- + I1 is I - 1, + J1 is J - 1, + pascal(I1, J, N1), + pascal(I1, J1, N2), + N is N1 + N2. +''' diff --git a/prolog/problems/old_exams/pascal_3/en.py b/prolog/problems/old_exams/pascal_3/en.py new file mode 100644 index 0000000..31a0d47 --- /dev/null +++ b/prolog/problems/old_exams/pascal_3/en.py @@ -0,0 +1,26 @@ +id = 179 +name = 'pascal/3' +slug = 'pascal's triangle' + +description = '''\ +<p>The first five rows of the Pascal's triangle look like this:</p> +<pre> + 1 + 1 1 + 1 2 1 + 1 3 3 1 + 1 4 6 4 1 +</pre> +<p> +Each row begins and ends with 1. Every other element can be obtained as a sum of the two values above it. Write the predicate <code>pascal(I,J,N)</code> that returns the <code>J</code>-th value in the <code>I</code>-th column of the Pascal's triangle. Your solution should return exactly one answer for any input (the <code>I</code> and <code>J</code> arguments start counting with 0; you can assume that 0 ≤ <code>J</code> ≤ <code>I</code>). + +<pre> + ?- pascal(0, 0, N). + N = 1. + ?- pascal(2, 1, N). + N = 2. + ?- pascal(4, 3, N). + N = 4. +</pre>''' + +hint = {} |