# 118. Pascal's Triangle """ given an integer 'num_rows', return the first numrows of pascal's triangle. in pascal's triangle, each number is the sum of the two number direction above it as show [gif] """ class Solution(object): def generate(self, num_rows): ans = [[1 for _ in range(row + 1)] for row in range(num_rows)] for row in range(num_rows): for col in range(1, row): ans[row][col] = ans[row - 1][col] + ans[row - 1][col - 1] return ans if __name__ == "__main__": obj = Solution() print(obj.generate(5)) # expect: [[1],[1,1],[1,2,1],[1,3,3,1],[1,4,6,4,1]] print(obj.generate(1)) # expect: [[1]]