std::vector<string> phrase1 {"the", "tigers", "of", "wrath"};
std::vector<string> phrase2 {"the", "horses", "of", "instruction"};
auto less = std::lexicographical_compare (std::begin (phrase1), std: :end (phrase1),
std::begin(phrase2), std::end(phrase2)); std::copy(std::begin(phrase1), std::end(phrase1), std::ostream_iterator<string>{std::cout, " "});
std::cout << (less ? "are":"are not") << " less than ";
std::copy(std::begin(phrase2), std::end(phrase2), std::ostream_iterator <string>{std::cout, " "});
std::cout << std::endl;
因为这些序列的第二个元素不同，而且“tigers”大于“horses”，这段代码会生成如下 输出：the tigers of wrath are not less than the horses of instruction
可以在 lexicographical_compare() 调用中添加一个参数，得到相反的结果：
auto less = std::lexicographical_compare (std::begin (phrase1), std::end (phrase1),std::begin(phrase2), std::end(phrase2), [](const string& s1, const string& s2) { return s1.length() < s2.length(); });
这个算法会使用作为第 3 个参数的 lambda 表达式来比较元素。这里会比较序列中字符串的长度，因为 phrase1 中第 4 个元素的长度小于 phrase2 中对应的元素，所以 phrase1 小于 phrase2。
本文链接：http://task.lmcjl.com/news/15500.html