杨辉三角--(补零法)

杨辉三角–补零法

a = [[1],[1,1]]

for i in range(2,6):
    newrow =a[i-1]
    newrow.append(0)
    row = [None] * (i+1)
    for j in range(i+1):
        row[j] = newrow[j]+newrow[j-1]
    a.append(row)
print(a)

初始方法

a =[]

for i in range(6):
    newrow =[1]
    a.append(newrow)
    if i ==0:
        continue
    lastrow =a[i-1]
    for j in range(i-1):
        newrow.append(lastrow[j]+lastrow[j+1])
    newrow.append(1)
print(a)