leetcode

#include <iostream>
#include <vector>
#include <string>

using namespace std;

class Solution {
public:
    string longestCommonPrefix(vector<string>& strs) {
        string ans="";
        if (strs.size() == 0) {
            return ans;
        }
        else if (strs.size() == 1) {
            ans = strs[0];
            return ans;
        }
        else {
            for (int i = 0, j = 0; i < strs[0].length(), j < strs[1].length(); i++, j++) {
                if (strs[ 0 ][ i ] == strs[ 1 ][ j ]) {
                    ans += strs[ 0 ][ i ];
                }
                else {
                    break;
                }
            }
            for (int i = 2; i < strs.size(); i++) {
                for (int j = 0, k = 0; j < strs[i].length(), k < ans.length(); j++, k++) {
                    if (strs[ i ][ j ] == ans[ k ]) {
                        continue;
                    }
                    else {
                        ans.erase(k);
                        break;
                    }
                }
            }
            return ans;
        }
    }
};


int main() {
    Solution solution;
    vector<string> str;
    string string1, result;
    while (cin >> string1 ) {
        str.push_back(string1);
    }
    result = solution.longestCommonPrefix(str);
    cout << result << endl;
    return 0;
}