【leetcode】Longest Common Prefix

Write a function to find the longest common prefix string amongst an array of strings.

 

class Solution {
public:
    string longestCommonPrefix(vector<string>& strs) {
        if(strs.size()==0) return "";

        string prefix=strs[0];

        for(int i=1;i<strs.size();i++)
        {
            if(prefix.size()==0||strs[i].size()==0) return "";

            
            int len=0;
            if(prefix.size()<strs[i].size())
                len=prefix.size();
            else
                len=strs[i].size();

            int j;
            for(j=0;j<len;j++)
            {
                if(prefix[j]!=strs[i][j])
                    break;
            }

            prefix=prefix.substr(0,j);
        }

        return prefix;
    }
};