Variation 1: Given row number r and column number c. Print the element at position (r, c) in Pascal’s triangle. Variation 2: Given the row number n. Print the n-th row of Pascal’s triangle. Variation ...

Given an index k, return the kth row of the Pascal’s triangle. Pascal’s triangle : To generate A[C] in row R, sum up A’[C] and A’[C-1] from previous row R - 1.