LeetCode 014 Longest Common Prefix

题目描述：Longest Common Prefix

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

代码如下：

class Solution {
public:
    string longestCommonPrefix(vector<string> &strs) {
        
        if(strs.empty()) return "";
        
        //用strs[0][0]与strs[1][0]、strs[2][0]……比较
        //用strs[0][1]与strs[1][1]、strs[2][1]……比较
        for(int index = 0; index < strs[0].size(); index++){
            for(int i = 1; i <strs.size(); i++){
                if(strs[i][index] != strs[0][index])
                    return strs[0].substr(0, index);
            }
        }
        
        return strs[0];
        
    }
};

 Java:

    public String longestCommonPrefix(String[] strs) {

        if (strs.length == 0) {
            return "";
        }

        for (int index = 0; index < strs[0].length(); index++) {
            
            for (int i = 0; i < strs.length; i++) {
                //要考虑后面字符串长度小的情况
                if (index < strs[i].length()) {
                    if (strs[i].charAt(index) != strs[0].charAt(index)) {
                        return strs[0].substring(0, index);
                    }
                }else {
                    return strs[i];
                }
                
            }
        }

        return strs[0];
    }