(1)计算1!+2!+……+n!。(先算阶乘,再算和)
sum = 0
xiaofeng = int(input("请输入数字:"))
for i in range(1, xiaofeng + 1):
a = 1
for j in range(1, i + 1):
a = a * j
sum += a
print("阶乘相加的数字为%s"%(sum))
(2)计算12-22+32-42+…+972-982+992
a = -1
sum = 0
for i in range(1, 100):
sum = sum + (-1) * a * i * i
a = a * (-1)
print(sum)
(3)一个数如果恰好等于它的因子这和,这个数就称为“完数”,例如,6的因子为1,2,3,而6=1+2+3,因此6就是“完数”。编程找出100内的所有完数。
for i in range(1,101):
sum=0
for j in range(1,i):
if(i%j==0):
sum+=j
if(sum==i):
print("100以内所有的完数有%d"%i)