[面试真题] LeetCode：Longest Common Prefix

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

class Solution {
public:
    string longestCommonPrefix(vector<string> &strs) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        stringstream rtn;
        int index = 0;
        if(strs.size() == 0){
            return rtn.str();
        }
        if(strs.size() == 1){
            return strs[0];
        }
        while(true){
            int i = 0;
            char ch = strs[i][index];
            if(ch != '\0'){
                for(; i<strs.size(); i++){
                    if(ch != strs[i][index]){
                        return rtn.str();
                    }
                } 
                rtn << ch;
                index++;
            }else{
                return rtn.str();
            }
        }
        return rtn.str();
    }
};

Run Status: Accepted!
Program Runtime: 28 milli secs

Progress: 117/117 test cases passed.