LeetCode OJ：Longest Common Prefix（最长公共前缀）

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

求很多string的公共前缀，用个两重循环就可以，代码如下：

class Solution {
public:
    string longestCommonPrefix(vector<string>& strs) {
        string prefix;
        if(strs.size() == 0 || strs[0].size() == 0)
            return "";
        int start = 0;
        bool endLoop = false;
        char cmp = strs[0][0];
        while(true && !endLoop){
            cout << cmp << endl;
            for(int i = 0; i < strs.size(); ++i){
                if(start >= strs[i].size() || cmp != strs[i][start]){
                    endLoop = true;
                    break;
                }
            }    
            if(!endLoop){
                start++;
                if(start < strs[0].size())
                    cmp = strs[0][start];
            }

        }
        return strs[0].substr(0, start - 1);
    }
};