Merge pull request #1515 from ivan1016017/january13

adding algo

Author: ivanpenaloza

src/my_project/interviews/top_150_questions_round_22/ex_46_summary_ranges.py

@@ -0,0 +1,30 @@
+from typing import List, Union, Collection, Mapping, Optional
+from abc import ABC, abstractmethod
+
+class Solution:
+    def summaryRanges(self, nums: List[int]) -> List[str]:
+
+        len_nums = len(nums)
+
+        if len_nums == 0:
+            return []
+        elif len_nums == 1:
+            return [f'{nums[0]}']
+        else:
+
+            answer = list()
+
+            pre = start = nums[0]
+
+            for i in nums[1:]:
+
+                if i - pre > 1:
+                    answer.append(f'{start}->{pre}' if pre - start > 0 else 
+                                  f'{start}')
+                    start = i
+
+                pre = i
+
+            answer.append(f'{start}->{pre}' if pre - start > 0 else f'{start}')
+
+            return answer

src/my_project/interviews/top_150_questions_round_22/ex_47_merge_intervals.py

@@ -0,0 +1,16 @@
+from typing import List, Union, Collection, Mapping, Optional
+from abc import ABC, abstractmethod
+
+class Solution:
+    def merge(self, intervals: List[List[int]]) -> List[List[int]]:
+
+        list_answer = list()
+
+        for i in sorted(intervals, key=lambda x: x[0]):
+
+            if list_answer and i[0] <= list_answer[-1][-1]:
+                list_answer[-1][-1] = max(list_answer[-1][-1], i[-1])
+            else:
+                list_answer.append(i)
+
+        return list_answer

tests/test_150_questions_round_22/test_46_summary_ranges_round_22.py

@@ -0,0 +1,24 @@
+import unittest
+from src.my_project.interviews.top_150_questions_round_22\
+.ex_46_summary_ranges import Solution
+
+class SummaryRangesTestCase(unittest.TestCase):
+
+    def test_empty(self):
+        solution = Solution()
+        output = solution.summaryRanges(nums=[])
+        target = []
+        self.assertEqual(target, output)
+
+    def test_single_element(self):
+        solution = Solution()
+        output = solution.summaryRanges(nums=[1])
+        target = ['1']
+        self.assertEqual(target, output)
+
+    def test_several_elements(self):
+        solution = Solution()
+        output = solution.summaryRanges(nums=[0,1,2,4,5,7])
+        target = ["0->2","4->5","7"]
+        for k, v in enumerate(target):
+            self.assertEqual(v, output[k])  

tests/test_150_questions_round_22/test_47_merge_intervals_round_22.py

@@ -0,0 +1,23 @@
+import unittest
+from src.my_project.interviews.top_150_questions_round_22\
+.ex_47_merge_intervals import Solution
+
+class MergeIntervalsTestCase(unittest.TestCase):
+
+    def test_first_pattern(self):
+        solution = Solution()
+        output = solution.merge(intervals = [[1,3],[2,6],[8,10],[15,18]])
+        target = [[1,6],[8,10],[15,18]]
+        self.assertEqual(output, target)
+
+    def test_second_pattern(self):
+        solution = Solution()
+        output = solution.merge(intervals = [[1,4],[4,5]])
+        target = [[1,5]]
+        self.assertEqual(output, target)
+
+    def test_third_pattern(self):
+        solution = Solution()
+        output = solution.merge(intervals = [[4,7],[1,4]])
+        target = [[1,7]]
+        self.assertEqual(output, target)