3 more challenges

Author: Shehab Abdel-Salam

ninja_challenges/exercises/challenge_19.py

@@ -0,0 +1,23 @@
+# Challenge 19 - Count Servers that Communicate
+# You are given a map of a server center, represented as a m * n integer matrix grid,
+# where 1 means that on that cell there is a server and 0 means that it is no server.
+# Two servers are said to communicate if they are on the same row or on the same column.
+# Return the number of servers that communicate with any other server.
+
+# Example 1:
+# Input: grid = [[1,0],[0,1]]
+# Output: 0
+# Explanation: No servers can communicate with others.
+
+# Example 2:
+# Input: grid = [[1,0],[1,1]]
+# Output: 3
+# Explanation: All three servers can communicate with at least one other server.
+
+# Example 3:
+# Input: grid = [[1,1,0,0],[0,0,1,0],[0,0,1,0],[0,0,0,1]]
+# Output: 4
+# Explanation: The two servers in the first row can communicate with each other.
+
+
+def count_servers(grid: list[list[int]]) -> int: ...

ninja_challenges/exercises/challenge_20.py

@@ -0,0 +1,22 @@
+# Challenge 20 - Integer to Roman
+# Seven Roman numerals are represented by the following symbols: I, V, X, L, C, D, and M.
+#
+# Symbol       Value
+# I             1
+# V             5
+# X             10
+# L             50
+# C             100
+# D             500
+# M             1000
+
+# Your task is to convert an integer to a Roman numeral.
+
+# Roman numerals are formed by appending the conversions of decimal place values from highest to lowest. Converting a decimal place value into a Roman numeral has the following rules:
+
+# If the value does not start with 4 or 9, select the symbol of the maximal value that can be subtracted from the input, append that symbol to the result, subtract its value, and convert the remainder to a Roman numeral.
+# If the value starts with 4 or 9 use the subtractive form representing one symbol subtracted from the following symbol, for example, 4 is 1 (I) less than 5 (V): IV and 9 is 1 (I) less than 10 (X): IX. Only the following subtractive forms are used: 4 (IV), 9 (IX), 40 (XL), 90 (XC), 400 (CD) and 900 (CM).
+# Only powers of 10 (I, X, C, M) can be appended consecutively at most 3 times to represent multiples of 10. You cannot append 5 (V), 50 (L), or 500 (D) multiple times. If you need to append a symbol 4 times use the subtractive form.
+
+
+def integer_to_roman(num: int) -> str: ...

ninja_challenges/exercises/challenge_21.py

@@ -0,0 +1,21 @@
+# Challenge 21 - Interval List Intersections
+# Given two lists of closed intervals, each list of intervals is pairwise disjoint and in sorted order.
+# Return the intersection of these two interval lists.
+# A closed interval [a, b] (with a < b) denotes the set of real numbers x with a <= x <= b.
+# The intersection of two closed intervals is a set of real numbers that are either empty or represented as a closed interval.
+# For example, the intersection of [1, 3] and [2, 4] is [2, 3].
+#
+# Example 1:
+# Input: first_list = [[0,2],[5,10],[13,23],[24,25]],
+#        second_list = [[1,5],[8,12],[15,24],[25,26]]
+# Output: [[1,2],[5,5],[8,10],[15,23],[24,24],[25,25]]
+#
+# Example 2:
+# Input: first_list = [[1,3],[5,9]],
+#        second_list = []
+# Output: []
+
+
+def interval_intersection(
+    first_list: list[list[int]], second_list: list[list[int]]
+) -> list[list[int]]: ...

ninja_challenges/tests/test_ninja_challenges.py

@@ -16,6 +16,9 @@
 from ..exercises.challenge_16 import is_word_in_matrix
 from ..exercises.challenge_17 import compare_versions
 from ..exercises.challenge_18 import NestedIterator
+from ..exercises.challenge_19 import count_servers
+from ..exercises.challenge_20 import integer_to_roman
+from ..exercises.challenge_21 import interval_intersection
 
 
 def test_challenge_01():
@@ -155,3 +158,32 @@ def test_challenge_18():
     assert iterator2.next() == 8
     assert iterator2.next() == 9
     assert iterator2.hasNext() is False
+
+
+def test_challenge_19():
+    assert count_servers([[1, 0], [0, 1]]) == 0
+    assert count_servers([[1, 0], [1, 1]]) == 3
+    assert count_servers([[1, 1, 0, 0], [0, 0, 1, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) == 4
+    assert count_servers([[1, 0, 0], [0, 0, 1], [0, 0, 1]]) == 3
+    assert count_servers([[1, 0, 0], [0, 1, 1], [0, 0, 1]]) == 4
+    assert count_servers([[1, 0, 0], [0, 1, 1], [0, 0, 0]]) == 2
+
+
+def test_challenge_20():
+    assert integer_to_roman(3) == "III"
+    assert integer_to_roman(4) == "IV"
+    assert integer_to_roman(9) == "IX"
+    assert integer_to_roman(58) == "LVIII"
+    assert integer_to_roman(1994) == "MCMXCIV"
+    assert integer_to_roman(3999) == "MMMCMXCIX"
+    assert integer_to_roman(39999) == "MMM"
+
+
+def test_challenge_21():
+    assert interval_intersection(
+        [[0, 2], [5, 10], [13, 23], [24, 25]], [[1, 5], [8, 12], [15, 24], [25, 26]]
+    ) == [[1, 2], [5, 5], [8, 10], [15, 23], [24, 24], [25, 25]]
+    assert interval_intersection([[1, 3], [5, 9]], []) == []
+    assert interval_intersection([[1, 7]], [[3, 10]]) == [[3, 7]]
+    assert interval_intersection([[1, 7]], [[8, 10]]) == []
+    assert interval_intersection([[1, 7]], [[7, 10]]) == [[7, 7]]