python第二章

目录

7-1 计算 11+12+13+...+m

7-2 计算分段函数[1]

7-3 阶梯电价

7-4 求奇数分之一序列前N项和

7-5 求交错序列前N项和

7-6 产生每位数字相同的n位数

7-7 转换函数使用

7-8 比较大小

7-9 输出华氏-摄氏温度转换表

7-10 求平方与倒数序列的部分和

7-11 偶数位特殊序列和

7-12 输出三角形面积和周长

7-13 分段计算居民水费

7-14 求整数段和

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7-1 计算 11+12+13+...+m

result = num = int(input())
 
for z in range(11, num):
    result += z
 
print("sum = %d" % result)

N = int(input()) + 1
print("sum = " + str(sum([x for x in range(11, N)])))

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7-2 计算分段函数[1]

x = float(input())
result = 0 if x == 0 else 1 / x
print("f(%.1f) = %.1f" % (x, result))

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7-3 阶梯电价

figure = float(input())
result = 0.53*figure if figure<=50 else 26.5+(figure-50)*0.58
 
if figure>0 :
    print("cost = %.2f"%(result))
else :
    print("Invalid Value!")

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7-4 求奇数分之一序列前N项和

N = int(input())
result = 1.0
for z in range(1,N):
    result += 1.0 / (z * 2 + 1)
print("sum = %.6f" % result)

N = int(input()) * 2
print("sum = %.6f" % sum([1 / x for x in range(1, N, 2)]))

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7-5 求交错序列前N项和

N = int(input())
result = flag = 1.0
 
for z in range(2,N+1):
    flag = -flag
    result += flag * z / (z*2-1)
 
print("%.3f" % result)

N = int(input()) + 1
print("%.3f" % sum([x / (x * 2 - 1) if x % 2 == 1 else -x / (x * 2 - 1) for x in range(1, N)]))

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7-6 产生每位数字相同的n位数

N,M = map(int,input().split(','))
for z in range(0,M):
    print("%d" % N,end='')

N, M = map(int, input().split(','))
print(sum([N * (10 ** x) for x in range(0, M)]))

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7-7 转换函数使用

num, flag = map(int, input().split(','))
result = 0
op = 1
 
while num > 0:
    result += num % 10 * op
    op *= flag
    num //= 10
 
print("%.f"%result)

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7-8 比较大小

a, b, c = map(int, input().split())
if a > b: (a, b) = (b, a)
if a > c: (a, c) = (c, a)
if b > c: (b, c) = (c, b)
 
print("%d->%d->%d" % (a, b, c))

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7-9 输出华氏-摄氏温度转换表

a, b = map(int, input().split())
    
if a > b or b > 100:
    print('Invalid.')
else:
    print('fahr celsius')
    while a <= b:
        print("%d%6.1f" % (a, 5.0 * (a - 32) / 9))
        a += 2

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7-10 求平方与倒数序列的部分和

a, b = map(int, input().split())
result = 0.0
for index in range(a, b + 1):
    result += index * index + 1 / index
 
print("sum = %.6f" % result)

N, M = map(int, input().split())
print("sum = %.6f" % sum([x*x+1/x for x in range(N,M+1)]))

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7-11 偶数位特殊序列和

a, b = map(int, input().split())
result = op = a*10+a
 
for index in range(2, b, 2):
    op = op*100+a*10+a
    result += op
 
print(result)

A, N = map(int, input().split())
print(sum([sum([A * (10 ** y) for y in range(x)]) for x in range(2, N + 1, 2)]))

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7-12 输出三角形面积和周长

import math
 
a, b, c = map(int, input().split())
if a + b > c and a + c > b and b + c > a:
    s = (a + b + c) / 2.0
    area = math.sqrt(s * (s - a) * (s - b) * (s - c))
    print("area = %.2f; perimeter = %.2f" % (area, a+b+c))
 
else:
    print("These sides do not correspond to a valid triangle")

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7-13 分段计算居民水费

x = float(input())
y = 4*x/3 if x<=15 else 2.5*x-17.5
print("%.2f"%y)

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7-14 求整数段和

head, tail = map(int, input().split())
result = flag = 0 # 结果 and 判断换行
 
for index in range(head, tail + 1):
    if flag % 5 == 0 and flag>0: print()
    flag += 1
    result += index
    print("%5d" % index, end='')
 
print("\nSum = %d" % result)

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