字符串数组最长公共前缀

#include <iostream>
#include <vector>
using namespace std;

string str_longest_prefix(string str1, string str2) {
    if (str1 == "" || str2 == "") {
        return "";
    }

    int i = 0, j = 0;
    string result = "";

    while (i < str1.size() && j < str2.size()) {
        if (str1[i] == str2[j]) {
            result += str1[i];
        }
        i++;
        j++;
    }

    return result;
}

string arr_longest_prefix(vector<string> arrs, int left, int right) {
    if (left >= right) {
        return arrs[left];
    }

    int mid = left + (right - left) / 2;
    string left_longest_prefix = arr_longest_prefix(arrs, left, mid);
    string right_longest_prefix = arr_longest_prefix(arrs, mid+1, right);
    return str_longest_prefix(left_longest_prefix, right_longest_prefix);
}

int main() {
    vector<string> arrs;
    arrs.push_back("flower");
    arrs.push_back("flow");
    arrs.push_back("flight");

    cout << arr_longest_prefix(arrs, 0, arrs.size()-1) << endl;
    return 0;
}