Leetcode-1087 permutation of letters(字母切换)

 1 #define _for(i,a,b) for(int i = (a);i < b;i ++)
 2 class Solution
 3 {
 4     public:
 5         vector<string> rnt;
 6         vector<string> LIST;
 7         int n;
 8         void dfs(int cur,string s)
 9         {
10             if(cur==n)
11             {
12                 rnt.push_back(s);
13                 return ;
14             }
15             _for(i,0,LIST[cur].size())
16             {
17                 dfs(cur+1,s+LIST[cur][i]);
18             }
19         }
20         vector<string> permute(string S)
21         {
22             vector<string> li(100);
23             n = 0;
24             int in = 0;
25             int st = 0;
26             _for(i,0,S.size())
27             {
28                 if(S[i]==‘,‘)
29                     continue;
30                 if(S[i]==‘{‘)
31                 {
32                     st = 1;
33                 }
34                 else if(S[i]==‘}‘)
35                 {
36                     st = 0;
37                     in ++;
38                     n ++;
39                 }
40                 
41                 else if(st==1)
42                     li[in].push_back(S[i]);
43                 else if(st==0)
44                 {
45                     li[in++].push_back(S[i]);
46                     n ++;
47                 }
48             }
49             LIST = li;
50             string ss;
51             dfs(0,ss);
52             sort(rnt.begin(),rnt.end());
53             return rnt;
54         }
55 };