Leetcode-935 knight-dialer(骑士拨号器) 

 1 #define _for(i,a,b) for(int i = (a);i < (b);i ++)
 2 #define _rep(i,a,b) for(int i = (a);i <= (b);i ++)
 3 typedef long long int ll;
 4 
 5 class Solution
 6 {
 7     private:
 8         vector<vector<int>> dialList {{4,6},{6,8},{7,9},{4,8},{0,3,9},{},{0,1,7},{2,6},{1,3},{2,4}};
 9         const int MOD = 1000000007;
10     public:
11         int knightDialer(int N)
12         {
13             vector<ll> dp (11,1);
14             int flag = 1;
15             while(-- N)
16             {
17                 vector<ll> tmp = dp;
18                 if(!flag)
19                 {
20                     _for(i,0,10)
21                     dp[i] = 0;
22                 }
23                 _for(i,0,10)
24                 {
25                     for(auto d:dialList[i])
26                         dp[d] = (dp[d]+tmp[i]) % MOD;
27                 }
28                 if(flag)
29                 {
30                     _for(i,0,10)
31                     {
32                         dp[i] --;
33                         flag = 0;
34                     }
35                 }
36             }
37             int result = 0;
38             _for(i,0,10)
39             {
40                 result = (result+dp[i]) % MOD;
41             }
42             return result;
43         }
44 };

 

posted @ 2018-11-06 18:27  Asurudo  阅读(435)  评论(0)    收藏  举报