使用模板将几个向量中的所有元素合并为一个

#include <iostream>
#include <vector>

template<typename T>
std::vector<T> mergeVectors(const std::vector<std::vector<T>>& vectors) {
    std::vector<T> mergedVector;
    for (const auto& vector : vectors) {
        mergedVector.insert(mergedVector.end(), vector.begin(), vector.end());
    }
    return mergedVector;
}

int main() {
    std::vector<std::vector<int>> vectors = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};
    std::vector<int> mergedVector = mergeVectors(vectors);

    for (const auto& element : mergedVector) {
        std::cout << element << " ";
    }
    std::cout << std::endl;

    return 0;
}