//2019招银信用中心,比特币最佳买卖时机
    //暴力解法
    //时间复杂度: O(n^2)
    //空间复杂度: O(n)
    void bitCoint() {
        string ss;
        getline(cin, ss);
        istringstream myStream(ss);
                //当数组长度未知时创建数组的方法
        vector<int> price((istream_iterator<int>(myStream)), istream_iterator<int>());
        int len = price.size();
        int maxi = 0;
        for (int i = 0; i < len; i++) {
            for (int j = i + 1; j < len; j++) {
                maxi = max(price[j] - price[i], maxi);
            }
        }
        cout << maxi << endl;
    }

    //2019招银信用中心,比特币最佳买卖时机
    //优化贪婪算法
    //时间复杂度: O(n)
    //空间复杂度: O(n)
    void bitCointTwo() {
        string ss;
        getline(cin, ss);
        istringstream myStream(ss);
        vector<int> price((istream_iterator<int>(myStream)), istream_iterator<int>());
        int len = price.size();
        int maxprofit = 0; //最大收益
        int minPrice = price[0]; //最小购入金
        for (int i = 0; i < len; i++) {
            maxprofit = max(price[i] - minPrice, maxprofit);
            minPrice = min(price[i], minPrice);
        }
        cout << maxprofit << endl;
    }