[LeetCode] Longest Common Prefix

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 lower-case English letters.

class Solution {
public:
    string longestCommonPrefix(vector<string>& strs) {
        string str = "";
        if (strs.size() == 1)
        {
            str = strs[0];
        }
        else
        {
            for (int i = 1 ; i <= strs[0].length(); i++)
            {
                string temp = strs[0].substr(0, i);
                for (int j = 1; j < strs.size(); j++)
                {
                    if (strs[j].find(temp) == 0)
                    {
                        if (j == strs.size() - 1)
                        {
                            str = temp; 
                        }
                    }
                    else
                    {
                        break;
                    }
                }
            }
        }
        return str;
    }
};