# 118. Pascal's Triangle
"""
given an integer 'numRows', 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, numRows):
ans = [[1]]
for i in range(1, numRows):
ans += [map(lambda x, y: x + y, ans[-1] + [0], [0] + ans[-1])]
return ans[:numRows]
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]]
