Pascal's Triangle 1

Given a non-negative integer numRows, generation ago with numRows Yang Hui Triangle.

Pascal's Triangle, each number is the number of its top left and top right and.

Code:

dlt = []
for i in range(1,6):
b = 0
lt = []
lt.append(1)
if i > 2: #第三层
# for j in range(i):
for k in range(i-2):
nub = dlt[i-2][b] + dlt[i-2][b+1]
lt.append(nub)
b = b +1
lt.append(1)
elif i == 2:
lt.append(1)
dlt.append(lt)
print(dlt)