[20180410] easy problems

Author: iamminji

README.md

@@ -14,6 +14,7 @@
 | [0009](https://leetcode.com/problems/palindrome-number/)                                               | Palindrome Number                                   | easy       | [python](🙂easy/0009.Palindrome-Number/palindrome_number.py)         |           |
 | [0011](https://leetcode.com/problems/container-with-most-water/)                                               | Container With Most Water                                   | medium       | [python](🤔medium/0011.Container-With-Most-Water/container_with_most_water.py)         |           |
 | [0013](https://leetcode.com/problems/roman-to-integer/description/)                          | Roman to Integer                          | easy       | python         |           |
+| [0014](https://leetcode.com/problems/longest-common-prefix/)                          | Longest Common Prefix                          | easy       | [python](🙂easy/0014.Longest-Common-Prefix/longest_common_prefix.py)         |           |
 | [0020](https://leetcode.com/problems/valid-parentheses/description/)                         | Valid Parentheses                         | easy       | python         |           |
 | [0021](https://leetcode.com/problems/merge-two-sorted-lists/description/)                    | Merge Two Sorted Lists                    | easy       | python         |           |
 | [0022](https://leetcode.com/problems/generate-parentheses/description/)                      | Generate Parentheses                      | medium     | python         |           |
@@ -41,6 +42,7 @@
 | [0169](https://leetcode.com/problems/majority-element/description/)                          | Majority Element                          | easy       | python         |           |
 | [0179](https://leetcode.com/problems/largest-number/description/)                            | Largest Number                            | medium     | python         |           |
 | [0182](https://leetcode.com/problems/duplicate-emails/)                            | Duplicate Emails                            | easy     | [sql](🙂easy/0182.Duplicate-Emails/duplicate_emails.sql)         |           |
+| [0189](https://leetcode.com/problems/rotate-array/)                            | Rotate Array                            | easy     | [python](🙂easy/0189.Rotate-Array/rotate_array.py)         |           |
 | [0199](https://leetcode.com/problems/binary-tree-right-side-view/description/)               | Binary Tree Right Side View               | medium     | python         |           |
 | [0200](https://leetcode.com/problems/number-of-islands/description/)                         | Number of Islands                         | medium     | java           |           |
 | [0203](https://leetcode.com/problems/remove-linked-list-elements/)                         | Remove Linked List Elements                         | easy     | [python](🙂easy/0203.Remove-Linked-List-Elements/remove_linked_list_elements.py)           |           |

🙂easy/0014.Longest-Common-Prefix/longest_common_prefix.py

@@ -0,0 +1,39 @@
+# 14. Longest Common Prefix
+# https://leetcode.com/problems/longest-common-prefix/
+
+from typing import List
+
+
+class Solution:
+    # 문자열 리스트에서 가장 긴 prefix 를 찾는 문제다.
+    def longestCommonPrefix(self, strs: List[str]) -> str:
+
+        # 문자열을 제일 긴 순서대로 정렬해서 전체 순회하여 가장 긴 prefix 를 찾았다.
+        strs = sorted(strs, key=lambda x: len(x), reverse=True)
+
+        if len(strs) == 0:
+            return ""
+        elif len(strs) == 1:
+            return strs[0]
+
+        prefix = strs[0]
+        for i in range(1, len(strs)):
+            p, q = 0, 0
+            res = ""
+            while p < len(prefix) and q < len(strs[i]) and prefix[p] == strs[i][q]:
+                res += prefix[p]
+                p += 1
+                q += 1
+
+            if res != "":
+                prefix = res
+            else:
+                return ""
+
+        return prefix
+
+
+if __name__ == '__main__':
+    sol = Solution()
+    assert sol.longestCommonPrefix(["flower", "flow", "flight"]) == "fl"
+    assert sol.longestCommonPrefix(["a", "a", "b"]) == ""

🙂easy/0189.Rotate-Array/rotate_array.py

@@ -0,0 +1,26 @@
+# 189. Rotate Array
+# https://leetcode.com/problems/rotate-array/
+
+from typing import List
+
+
+class Solution:
+    def rotateTLE(self, nums: List[int], k: int) -> None:
+        """
+        Do not return anything, modify nums in-place instead.
+        """
+        for _ in range(k):
+            nums[0], nums[1:len(nums)] = nums[len(nums) - 1], nums[:len(nums) - 1]
+
+    def rotate(self, nums: List[int], k: int) -> None:
+        """
+        Do not return anything, modify nums in-place instead.
+        """
+        k = k % len(nums)
+        nums[:] = nums[-k:] + nums[:-k]
+
+
+if __name__ == '__main__':
+    sol = Solution()
+    print(sol.rotate([1, 2, 3, 4, 5, 6, 7, 8], 4))
+    print(sol.rotate([1, 2, 3, 4, 5], 3))