14. Longest Common Prefix

class Solution {
public:
    string longestCommonPrefix(vector<string>& strs) {
        string tmp="";
        int n=strs.size();
        if(n==0)
            return tmp;
        int i,j;
        for(i=0;i<strs[0].size();i++)
        {
            char c=strs[0][i];
            for(j=0;j<n;j++)
            {
                if(i>=strs[j].size()||strs[j][i]!=c)
                    return tmp;
            }
            tmp+=c;
        }
        return tmp;
    }
};