Leetcode题解（十一）

 1 class Solution {
 2 public:
 3     void nextPermutation(vector<int>& nums) {
 4         const int size = nums.size();
 5         int temp,left,right;
 6         if(size <= 1)
 7             return;
 8 
 9         if(2 == size)
10         {
11             temp = nums[0];
12             nums[0] = nums[1];
13             nums[1] = temp;
14             return;
15         }
16 
17         int index = size-1-1;//从倒数第二个开始
18 
19         while (index>=0)
20         {
21             if(nums[index] >= nums[index + 1])//等号很重要，比如（5,1,1）的情况
22                 index--;
23             else
24                 break;
25         }
26 
27 
28 
29         if(index>=0)
30         {
31             right = size - 1;
32             while(right > index)
33             {
34                 if(nums[right] <= nums[index])//等号很重要，比如（5,1,1）的情况
35                     right--;
36                 else
37                     break;
38             }
39 
40             if(right>index)
41             {
42                 temp = nums[right];
43                 nums[right] = nums[index];
44                 nums[index] = temp;
45             }
46             left = (++index);
47         }
48         else
49             left = 0;
50 
51         right = size-1;
52 
53         while (left <= right)
54         {
55             temp = nums[right];
56             nums[right] = nums[left];
57             nums[left] = temp;
58             left++;
59             right--;
60         }
61 
62     }
63 };