2019-03-07day4作业

读程序，总结程序的功能:

numbers=1
for i in range(0,20):
 numbers*=2
print(numbers)

2的20次方

summation=0
num=1
while num<=100:
 if (num%3==0 or num%7==0) and num%21!=0:
 summation += 1
 num+=1
print(summation)

求100以内能整除3或乘除7并且不整除21的数的个数
编程实现(for和while各写⼀遍):

1. 求1到100之间所有数的和、平均值

sum = 0
for x in range(1,101):
    sum +=x
print(sum,sum/100)
# 5050  # 50.5

n = 1
sum = 0
while n <= 100:
    sum += n
    n += 1
print(sum)

2. 计算1-100之间能3整除的数的和

sum = 0
for x in range(1,101):
    if x % 3 == 0:
        sum += x
print(sum)

sum = 0
n = 1
while n <= 100:
    if n %3 == 0:
        sum+=n
        if n == 100:
            break
    n+=1
print(sum)

3. 计算1-100之间不能被7整除的数的和

sum = 0
for x in range(1,101):
    if x %7 != 0:
        sum+=x
print(sum)


sum = 0
n = 1
while n <= 100:
    if n % 7 != 0:
        sum+=n
        if n == 100:
            break
    n +=1
print(sum)