leetcode-next permutation

EdgeCase太容易出错。有两处都是应该为<=但写成了<。

 1 #include <iostream>
 2 #include <vector>
 3 #include <algorithm>
 4 using namespace std;
 5 
 6 class Solution2 {
 7 public:
 8     void nextPermutation(vector<int> &num) {
 9         int last = num.size() - 1;
10     }
11 };
12 class Solution {
13 public:
14     void nextPermutation(vector<int> &num) {
15         int last = num.size() - 1;
16         int vioIndex = last;
17         while (vioIndex - 1 >= 0 && num[vioIndex] <= num[vioIndex - 1])//出错点！是<=不是<！[1,1]
18         {
19             vioIndex--;
20         }
21         if (vioIndex != 0)
22         {//存在vioIndex
23             vioIndex--;
24             int rightIndex = last;
25             while (num[rightIndex] <=num[vioIndex])//出错点。是<=,不是< [1,5,1]
26                 rightIndex--;
27             //swap vio and rightIndex
28             int temp = num[vioIndex];
29             num[vioIndex] = num[rightIndex];
30             num[rightIndex] = temp;
31             //reverse from vioIndex+1 to the end
32             vioIndex++;
33         }
34 
35         //不存在vioIndex.直接逆序就行了
36         int beg = vioIndex;
37         int end = last;
38         while (beg < end)
39         {
40             int temp = num[end];
41             num[end] = num[beg];
42             num[beg] = temp;
43             beg++; end--;
44         }
45 
46         //next_permutation(num.begin(), num.end());
47         printV(num);
48     }
49     void printV(vector<int> &num)
50     {
51         for (int i = 0; i < num.size(); i++)
52         {
53             //cout << (i == 0 ? num[i] : ',' << num[i]);
54             if (i == 0)
55                 cout << num[i];
56             else
57                 cout << ',' << num[i];
58         }
59         cout << endl;
60     }
61 };
62 int main()
63 {
64     Solution s;
65     int a[] = { 1,  1 };
66     vector<int> v(a, a + 2);
67     s.nextPermutation(v);
68     return 0;
69 }

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http://fisherlei.blogspot.com/2012/12/leetcode-next-permutation.html