14.longest-common-prefix.cpp

/*
 * @lc app=leetcode id=14 lang=cpp
 *
 * [14] Longest Common Prefix
 *
 * https://leetcode.com/problems/longest-common-prefix/description/
 *
 * algorithms
 * Easy (46.61%)
 * Likes:    20485
 * Dislikes: 4854
 * Total Accepted:    5.2M
 * Total Submissions: 11.2M
 * Testcase Example:  '["flower","flow","flight"]'
 *
 * 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: strs = ["flower","flow","flight"]
 * Output: "fl"
 * 
 * 
 * Example 2:
 * 
 * 
 * Input: strs = ["dog","racecar","car"]
 * Output: ""
 * Explanation: There is no common prefix among the input strings.
 * 
 * 
 * 
 * Constraints:
 * 
 * 
 * 1 <= strs.length <= 200
 * 0 <= strs[i].length <= 200
 * strs[i] consists of only lowercase English letters if it is non-empty.
 * 
 * 
 */

// @lc code=start
class Solution {
public:
    string longestCommonPrefix(vector<string>& strs) {
        string res = "";
        for(uint8_t i = 0; i < strs[0].size(); res += strs[0][i++])
            for(uint8_t j = 0; j < strs.size() - 1; j++)
                if (strs[j][i] ^ strs[j+1][i])
                    return res;
        return res;
    }
};
// @lc code=end