LeetCode： Permutations II 题解

 1 class Solution {
 2 public:
 3    vector<vector<int> > vi;
 4     vector<int> types;  // 数字缓存数组
 5     vector<int> counts; // 数字计数器数组
 6     vector<int> seq;    //  打印数组
 7 
 8     void generatePermute(int len)
 9     {
10         if(len==0)
11         {
12             vi.push_back(seq);
13             return;
14         }
15         for(int i=0;i<types.size();i++)
16         {
17             if((counts[i])>0)
18             {
19                 counts[i]--;
20                 seq[len-1]=types[i];    //第len-1 是否存放types[i]
21                 generatePermute(len-1);
22                 counts[i]++;
23             }
24         }
25     }
26 
27     vector< vector<int> > permuteUnique(vector<int> &num) {
28         
29         if(num.size()==0) return vi;
30         sort(num.begin(),num.end());
31         
32         vi.clear();      //结果数组初始化
33         types.clear();   //数字缓存数组初始化
34         counts.clear();  //计数器初始化
35         seq.resize(num.size());  //输出数组大小设定
36 
37         int j=0;
38         types.push_back(num[0]);
39         counts.push_back(1);
40 
41         for(int i=1;i<num.size();i++)
42         {
43             if(num[i]==types.back())
44             {
45                 counts.back()++;
46             }
47             else
48             {
49                 types.push_back(num[i]);
50                 counts.push_back(1);
51             }
52         }
53         generatePermute(num.size());
54         return vi;
55     }
56 };