全部代码
list_=[]
a=int(input("请输入杨辉三角的行数:"))
def bb(a):
for j in range(2,a+2):
ls = []
for i in range(1,j):
ls.append(i)
list_.append(ls)
for j in range(0,a):
list_[len(list_[j])-1][len(list_[j])-1]=1
def aa(list_):
j=2
k=2
c=3
for i in range(c,a):
list_[i][i-j]=list_[i-1][i-j]+list_[i-1][0]
j+=1
c += 1
for i in range(0,a-4):
for i in range(c,a):
list_[i][i-j]=list_[i-1][i-j]+list_[i-1][0]
list_[i][i - k] = list_[i - 1][i - j] + list_[i - 1][i - k]
j += 1
k += 1
c += 1
bb(a)
aa(list_)
for i in list_:
a-=1
print(" "*a,i)