Given k strings, find the longest common prefix (LCP).

Have you met this question in a real interview?

 

 

Example

For strings "ABCD", "ABEF" and "ACEF", the LCP is "A"

For strings "ABCDEFG", "ABCEFG" and "ABCEFA", the LCP is "ABC"

 

LeetCode上的原题，请参见我之前的博客。

 

解法一：

class Solution {public:        /**     * @param strs: A list of strings     * @return: The longest common prefix     */    string longestCommonPrefix(vector
       
         &strs) {        if (strs.empty()) return "";        string res = "";        for (int j = 0; j < strs[0].size(); ++j) {            char c = strs[0][j];            for (int i = 0; i < strs.size(); ++i) {                if (j >= strs[i].size() || strs[i][j] != c) return res;            }            res.push_back(c);        }        return res;    }};
       

 

解法二：

class Solution {public:        /**     * @param strs: A list of strings     * @return: The longest common prefix     */    string longestCommonPrefix(vector
       
         &strs) {        if (strs.empty()) return "";        for (int j = 0; j < strs[0].size(); ++j) {            for (int i = 0; i < strs.size() - 1; ++i) {                if (j >= strs[i].size() || j >= strs[i + 1].size() || strs[i][j] != strs[i + 1][j]) {                    return strs[i].substr(0, j);                }            }        }        return strs[0];    }};