【leetcode】Longest Common Prefix

 1 class Solution {
 2 public:
 3     string longestCommonPrefix(vector<string>& strs) {
 4         if(strs.size()==0) return "";
 5 
 6         string prefix=strs[0];
 7 
 8         for(int i=1;i<strs.size();i++)
 9         {
10             if(prefix.size()==0||strs[i].size()==0) return "";
11 
12             
13             int len=0;
14             if(prefix.size()<strs[i].size())
15                 len=prefix.size();
16             else
17                 len=strs[i].size();
18 
19             int j;
20             for(j=0;j<len;j++)
21             {
22                 if(prefix[j]!=strs[i][j])
23                     break;
24             }
25 
26             prefix=prefix.substr(0,j);
27         }
28 
29         return prefix;
30     }
31 };