小编jav*_*o10的帖子

我正在学习c ++中的递归,并坚持为什么你不能简单地使用.push_back()而不是创建一个函数来复制specific_previous_result元素,然后.push_back().

vector<vector<int>> get_every_n_elements(vector<int> arr, int n) {
if (n == 0) {
    vector<vector<int>> result;

    vector<int> empty_list;
    result.push_back(empty_list);

    return result;
}

vector<vector<int>> previous_result = get_every_n_elements(arr, n - 1);

vector<vector<int>> current_result; //empty

for (auto specific_previous_result : previous_result) { // [[]] -> []

    for (auto elem : arr) { // [1,2,3,4] -> 1
      //current_result.push_back(specific_previous_result.push_back(elem));
      //This does not work^^

      current_result.push_back(group(specific_previous_result, elem));
      //The group function copies all elements to newVec and push_back(elem) after
      //Then returns newVec with elem …