【leetcode】Edit Distance

 1 class Solution {
 2 public:
 3     int minDistance(string word1, string word2) {
 4        
 5         int n1=word1.length();
 6         int n2=word2.length();
 7        
 8         if(n1==0) return n2;
 9         if(n2==0) return n1;
10  
11         //采用二维数组效率更高 
12         //vector<vector<int> > dp(n1+1,vector<int>(n2+1));
13        
14         int **dp=new int*[n1+1];
15         for(int i=0;i<n1+1;i++)
16         {
17             dp[i]=new int[n2+1];
18         }
19        
20        
21         dp[0][0]=0;
22         for(int i=1;i<=n1;i++)
23         {
24             dp[i][0]=i;
25         }
26         for(int j=1;j<=n2;j++)
27         {
28             dp[0][j]=j;
29         }
30        
31         for(int i=1;i<=n1;i++)
32         {
33             for(int j=1;j<=n2;j++)
34             {
35                
36                 if(word1[i-1]==word2[j-1])
37                 {
38                     dp[i][j]=dp[i-1][j-1];
39                 }
40                 else
41                 {
42                     dp[i][j]=min(dp[i-1][j],min(dp[i][j-1],dp[i-1][j-1]))+1;
43                 }
44             }
45         }
46        
47         int result=dp[n1][n2];
48         for(int i=0;i<n1+1;i++)
49         {
50             delete[] dp[i];
51         }
52        
53         return result;
54     }
55 };