std :: sort检查向量是否已经排序？

#include<iostream>
#include<vector>
#include<algorithm>

int main() {
    std::vector<int> v = {1, 2, 3, 4, 5};
    std::cout << "Is the vector sorted? "<< std::is_sorted(v.begin(), v.end())<< std::endl;

    v[2] = 6;
    std::cout << "Is the vector sorted? "<< std::is_sorted(v.begin(), v.end())<< std::endl;

    return 0;
}

Is the vector sorted? 1
Is the vector sorted? 0