Stay button 14- longest common prefix Longest common prefix

topic

Write a function to find the longest common prefix string array

For example

Thinking

1. A two-dimensional array corresponding to an array of strings, to find the longest prefix corresponds to the longitudinal traverse, two pointers, a current value taken away laterally, a longitudinal pointer away, the underlying elements of the array at the same lateral string pointer comparing means referring to
2. Note that if there was to the end of the string has been traversed during traversal, we need to stop, do not forget this judgment conditions

Code

class Solution {
public:
    string longestCommonPrefix(vector<string>& strs) {
        if(strs.empty()) return "";
        string res = "";
        for(int j = 0; j<strs[0].size();++j)//j走横向
        {
            char c = strs[0][j];
            for(int i = 0; i<strs.size(); ++i)//i走纵向
            {
                if(j>=strs[i].size() || strs[i][j] != c)//遇到一个字符串已遍历完
                return res;
            }
            //每个字符串都ok就push_back到结果
            res.push_back(c);
        }
        return res;

    }
};