https://oj.leetcode.com/problems/pascals-triangle-ii/

Q119.cpp

class Solution {
  public:
    vector<int> getRow(int rowIndex) {
      if (rowIndex < 0) return vector<int>();
      vector<int> result{1};
      while (rowIndex-- > 0) {
        vector<int> tmp{1};
        for (auto start = result.begin() + 1; start != result.end(); start++) {
          tmp.push_back(*(start-1) + *start);
        }
        tmp.push_back(1);
        result = tmp;
      }
      return result;
    }
};