1.我的暴力解法:

class Solution {public static int shortestLen=0;public String longestCommonPrefix(String[] strs) {int min_length=getShortestStr(strs);String res="";int i=0,j=1;for (;i<min_length;i++){char ch=strs[0].charAt(i);boolean flag=true;j=1;if(min_length==1){for (;j<strs.length;j++){if(strs[j].charAt(0)!=strs[0].charAt(0)){return "";}}return ""+strs[0].charAt(0);}else{for (;j<strs.length;++j){if(ch!=strs[j].charAt(i)){return res;}}if(flag==true){res+=(ch);}}}return res;}public int getShortestStr(String[] str){int res=999;if(str==null){return -1;}int i=0;while(i<str.length){if(str[i].length()<res){res=str[i].length();}i++;}return res;}}

2.大佬解法

直接字符串排序,假设strs长度为n,则时间需要O(max(nlogn),shortest_str_len),一般也就是nlogn水平
CPP解法

class Solution {
public:string longestCommonPrefix(vector<string>& strs) {if(strs.empty())return string();sort(strs.begin(), strs.end());string st = strs.front(), en = strs.back();int i, num = st.size();for(i = 0; i < num && st[i] == en[i]; i ++);return string(st, 0, i);}
};