如何在c++中合并多个排序范围？

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

// 合并排序范围的函数
template<typename RandomIt>
void mergeRanges(RandomIt first1, RandomIt last1, RandomIt first2, RandomIt last2, RandomIt output)
{
    while (first1 != last1 && first2 != last2) {
        if (*first1 < *first2) {
            *output = *first1;
            ++first1;
        } else {
            *output = *first2;
            ++first2;
        }
        ++output;
    }
    // 将剩余的元素复制到输出范围
    std::copy(first1, last1, output);
    std::copy(first2, last2, output);
}

int main()
{
    std::vector<int> range1 = {1, 3, 5};
    std::vector<int> range2 = {2, 4, 6};
    std::vector<int> range3 = {0, 7, 8};

    std::vector<int> merged(range1.size() + range2.size() + range3.size());

    // 合并排序范围
    mergeRanges(range1.begin(), range1.end(), range2.begin(), range2.end(), merged.begin());
    mergeRanges(merged.begin(), merged.end(), range3.begin(), range3.end(), merged.begin());

    // 输出合并后的结果
    for (const auto& num : merged) {
        std::cout << num << " ";
    }
    std::cout << std::endl;

    return 0;
}