Longest Common Prefix

 1 public class Solution {
 2     public static String longestCommonPrefix(String[] strs) {
 3     if(strs.length==0){return "";}
 4     if(strs.length==1){return strs[0];}
 5     int len=strs.length;
 6     int index=0;
 7     boolean flag=false;
 8         for(int i=0;i<strs[0].length();i++){
 9             char x=strs[0].charAt(i);
10             for(int j=1;j<len;j++){
11             if(i>=strs[j].length()){flag=true;index=i;break;}
12             char y=strs[j].charAt(i);
13             if(x!=y){flag=true;index=i;break;}
14             }
15             if(flag){break;}
16             if(i==strs[0].length()-1){index=strs[0].length();}
17         }
18         String ans=strs[0].substring(0,index);
19         return ans;
20     }
21     public static void main(String[]args){
22     String[]strs=new String[2];
23     strs[0]="a";
24     strs[1]="a";
25     System.out.println(longestCommonPrefix(strs));
26     }
27 }