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

int main()
{
    std::vector<int> a = {...};
    std::sort(a.begin(), a.end(), [](int x, int y) { return x <= y; });
    for (int i : a) std::cout << i << ' ';
    return 0;
}

lambda 里写 <= 或 < 的效果都一样吗