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

Longest Common Prefix.cpp

class Solution {
public:
    string longestCommonPrefix(vector<string> &strs) {
        if(strs.size() == 0) {
            return "";
        }
        string prefix;
        int index = 0;
        
        while(true) {
            char* cur = NULL;
            for(int i = 0; i < strs.size(); ++i) {
                string& curStr = strs[i];
                if(curStr.length() == index) {
                    return prefix;
                } else {
                    if(cur == NULL) {
                        cur = new char(curStr[index]);
                    } else {
                        if(*cur != curStr[index]) {
                            return prefix;
                        }
                    }
                }
                
                
            }
            ++index;
            if(cur != NULL) {
                prefix.push_back(*cur);
                delete cur;
            }

        }

    }
};