Merge pull request #80 from tuyula/master

"第一周作业"

Author: GeekUniversity

Week_01/id_34/NOTE.md

@@ -1 +1,5 @@
 # 学习笔记
+感谢大佬们分享
+
+自己属于菜鸟一枚, 所以看到大佬们的各种思路有的激动, 这周写的题目不多, 只是完成了任务, 但是一题多解让我感觉到思考比答案更重要, 自己通过不断的看高手的解题, 不断加深自己的脑图,
+但是发现自己看到题目不会那么懵逼, 可以先遍历自己大脑思考一下

Week_01/id_34/leetcode-189.py

@@ -0,0 +1,70 @@
+from typing import List
+
+
+class Solution:
+    # 重伤, 提交代码说是执行时间过长 43333333
+    def rotate(self, nums: List[int], k: int) -> None:
+        """
+        Do not return anything, modify nums in-place instead.
+        """
+        n = len(nums)
+
+        if n == 0 or n == 1:
+            return
+
+        if k > n:
+            k = k % n
+
+        for i in range(k):
+            temp = nums[n - 1]
+            for j in range(n - 1, 0, -1):
+                nums[j] = nums[j - 1]
+            nums[0] = temp
+
+    # 和上面一样, 180 ms, 13.5 MB
+    def rotate2(self, nums: List, k: int) -> None:
+        """
+        Do not return anything, modify nums in-place instead.
+        """
+        n = len(nums)
+
+        if n == 0 or n == 1:
+            return
+
+        if k > n:
+            k = k % n
+
+        for _ in range(k):
+            nums.insert(0, nums.pop())
+
+    # 反转法, 72 ms, 13.2 MB
+    def rotate3(self, nums: List, k: int) -> None:
+        n = len(nums)
+
+        if n == 0 or n == 1:
+            return
+
+        if k > n:
+            k = k % n
+
+        self.reverse(nums=nums, s=0, end=n-1)
+        self.reverse(nums=nums, s=0, end=k-1)
+        self.reverse(nums=nums, s=k, end=n-1)
+
+    def reverse(self, nums: List, s: int, end: int):
+        while end > s:
+            nums[end], nums[s] = nums[s], nums[end]
+            end -= 1
+            s += 1
+
+    # 根据索引, 64 ms, 13.2 MB
+    def rotate4(self, nums: List, k: int) -> None:
+        n = len(nums)
+
+        if n == 0 or n == 1:
+            return
+
+        if k > n:
+            k = k % n
+
+        nums[:] = nums[-k:] + nums[:-k]

Week_01/id_34/leetcode-26.py

@@ -0,0 +1,22 @@
+from typing import List
+
+
+class Solution:
+    def removeDuplicates(self, nums: List[int]) -> int:
+        i = 0
+        for j in range(1, len(nums)):
+            if nums[i] != nums[j]:
+                i += 1
+                nums[i] = nums[j]
+        return i + 1 if nums else 0
+
+
+# 逆向, 但是没有原地排序
+class Solution2:
+    def removeDuplicates(self, nums: List[int]) -> int:
+        for i in range(len(nums)-1, 0, -1):
+            print(i)
+            if nums[i] == nums[i-1]:
+                nums.pop(i)
+        return len(nums) if nums else 0
+