leetcode75

class Solution {
public:
    void sortColors(vector<int>& nums) {
        sort(nums.begin(), nums.end());
    }
};

上面这个太弱了，给一个强不了多少的

 1 class Solution:    
 2     def sortColors(self, nums: 'List[int]') -> 'None':
 3         red = 0
 4         white = 0
 5         blue = 0
 6         for n in nums:
 7             if n == 0:
 8                 red+=1
 9             elif n == 1:
10                 white += 1
11             elif n == 2:
12                 blue += 1
13             else:
14                 print('error')
15         nums.clear()
16         nums.extend([0]*red + [1]*white + [2]*blue)

下面给出一个比较强的

 1 class Solution:    
 2     def swap(self,nums,i,j):
 3         nums[i],nums[j] = nums[j],nums[i]
 4         '''
 5         temp = nums[i]
 6         nums[i] = nums[j]
 7         nums[j] = temp
 8         '''
 9 
10     def sortColors(self, nums: 'List[int]') -> 'None':
11         n = len(nums)
12         left = 0
13         right = n - 1
14         i = 0
15         while i <= right:
16             if nums[i] == 0:
17                 if i != left:
18                     self.swap(nums,i,left)
19                 i += 1
20                 left += 1
21             elif nums[i] == 1:
22                 i += 1
23             else:
24                 self.swap(nums,i,right)

注意swap的写法，如果用temp来存，速度会慢很多。

posted on 2018-10-03 19:45 Sempron2800+ 阅读(129) 评论(0) 编辑收藏举报