feat: solve DaleStudy#280 with python

meeting-rooms-ii/EGON.py

@@ -0,0 +1,74 @@
+from typing import List
+from unittest import TestCase, main
+
+
+# Definition of Interval:
+class Interval(object):
+    def __init__(self, start, end):
+        self.start = start
+        self.end = end
+
+
+class Solution:
+    def minMeetingRooms(self, intervals: List[Interval]) -> int:
+        return self.solve_two_pointer(intervals)
+
+    """
+    LintCode 로그인이 안되어서 https://neetcode.io/problems/meeting-schedule-ii 에서 실행시키고 통과만 확인했습니다.
+
+    Runtime: ? ms (Beats ?%)
+    Time Complexity: O(n log n)
+        - intervals의 길이를 n이라 하면, starts를 정렬하는데 O(n log n)
+        - ends를 정렬하는데 O(n log n)
+        - intervals를 인덱스를 이용해 전체 조회하는데 O(n)
+        > O(n log n) * 2 + O(n) ~= O(n log n)
+
+    Memory: ? MB (Beats ?%)
+    Space Complexity: O(n)
+        - starts와 ends의 크기는 intervals와 같으므로 O(n)
+        - 포인터로 index를 사용했으므로 O(1)
+        > O(n) + O(1) ~= O(n)
+    """
+    def solve_two_pointer(self, intervals: List[Interval]) -> int:
+        if not intervals:
+            return 0
+
+        starts, ends = sorted([i.start for i in intervals]), sorted([i.end for i in intervals])
+        start_idx, end_idx = 0, 0
+        schedule_count = 0
+        while start_idx < len(intervals):
+            if starts[start_idx] < ends[end_idx]:
+                schedule_count += 1
+                start_idx += 1
+            else:
+                end_idx += 1
+                start_idx += 1
+
+        return schedule_count
+
+
+class _LeetCodeTestCases(TestCase):
+    def test_1(self):
+        intervals = [Interval(0,40), Interval(5,10), Interval(15,20)]
+        output = 2
+        self.assertEqual(Solution().minMeetingRooms(intervals), output)
+
+    def test_2(self):
+        intervals = [Interval(4, 9)]
+        output = 1
+        self.assertEqual(Solution().minMeetingRooms(intervals), output)
+
+    def test_3(self):
+        intervals = [
+            Interval(1, 5),
+            Interval(2, 6),
+            Interval(3, 7),
+            Interval(4, 8),
+            Interval(5, 9),
+        ]
+        output = 4
+        self.assertEqual(Solution().minMeetingRooms(intervals), output)
+
+
+if __name__ == '__main__':
+    main()