Leetcode 14. Longest Common Prefix(水)

14. Longest Common Prefix

Easy

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

If there is no common prefix, return an empty string "".

Example 1:

Input: ["flower","flow","flight"]
Output: "fl"

Example 2:

Input: ["dog","racecar","car"]
Output: ""
Explanation: There is no common prefix among the input strings.

Note:

All given inputs are in lowercase letters a-z.

 class Solution {
 public:
     string longestCommonPrefix(vector<string>& strs) {
         int top = ;
         int fl = ;
         int len = strs.size();
         if(len==) return "";
         if(len==) return strs[];
         while(fl){
             for (int i =  ;i < len; i++){
                 if(top>strs[i].length()||top>strs[i-].length()||strs[i][top]!=strs[i-][top]){
                     fl = ;
                     break;
                 }
             }
             top++;
         }
         top--;
         if(top==) return "";
         return strs[].substr(,top);
     }
 };