第五章-数字 课后答案

5-1

普通整型和长整型能表示的数据的位数不同。用大写字母"L"加在后面表示长整型，目前整型和长整型正在逐渐缓慢的统一。

5-2

(a)

def plus(a, b):
    return a*b;

(b)

>>>plus(4, 5)
20

5-3

def scoreOut(x):
    scoreDic = {9:"A",8:"B",7:"C",6:"D"}
    score  = x / 10
    for item in sorted(scoreDic.keys(),reverse = True):
        if score >= item:
            out = scoreDic[item]
            break
        else:
            out = "F"
    return out

score = input("Enter your number,Please!")
print "Your level is: %s" % scoreOut(score)

 5-4

def leap_year(n):
    if (n % 4==0 and n % 100!=0) or n % 400==0:
        return "is";
    else:
        return "is not";

year = input("Please input the year: ");
print "Year %d %s a leap year!" % (year, leap_year(year))

5-5

def cal_money(x):
    cent_25 = x/25
    cent_10 = (x - 25 * cent_25)/10
    cent_5 = (x - 25 * cent_25 - 10 * cent_10)/5
    cent_1 = x - 25 * cent_25 - 10 * cent_10 - 5 * cent_5
    return cent_25,cent_10,cent_5,cent_1

cent = input("input your cent,please: ")
a, b, c, d = cal_money(cent)
print "%d convert to %d 25cent, %d 10cent, %d 5cent, %d 1cent" % (cent, a, b, c, d)

5-6

def calculate(str):
    sList = str.split(" ")
    if sList[1] == "+":
        return int(sList[0])+int(sList[2])
    elif sList[1] == "-":
        return int(sList[0])-int(sList[2])
    elif sList[1] == "*":
        return int(sList[0])*int(sList[2])
    elif sList[1] == "/":
        return int(sList[0])/int(sList[2])
    elif sList[1] == "%":
        return int(sList[0])%int(sList[2])
    elif sList[1] == "**":
        return int(sList[0])**int(sList[2])
    else:
        return "error operator"

while True:
    strEval = raw_input("please input the eval(q to quit): ")
    if strEval.lower() == "q":
        break
    print "the result is %d" % (calculate(strEval))

 5-8

def square(x):
    return x*x

def cube(x):
    return x*x*x

import math
def circle(x):
    return math.pi * x * x

def ball(x):
    return 4.0/3 * math.pi * r * r * r

5-9

(a)因为017等数字代表的是八进制数字

(b)56和78后面的是字母l，不是数字1，表示的是长整型

5-10

def temperature(x):
    return (x - 32) * (5.0/9.0)

if __name__ == "__main__":
    strTem = input("input the temperature,please: ")
    print "the result is: %f" % temperature(strTem)

 5-11

(a)

def odd():
    aList = []
    for i in range(21):
        if i%2 == 0:
            aList.append(i)
    return aList

(b)

def even():
    aList = []
    for i in range(21):
        if i%2 == 1:
            aList.append(i)
    return aList

(c)

取余

(d)

def calculate():
    number_a = input("Please input a integer: ")
    number_b = input("Please input another integer: ")
    if number_a % number_b == 0 or number_b % number_a == 0:
        return True
    else:
        return False

5-12

import sys;     #加载sys模块

#整数的范围，超过则自动转换为长整数
print (sys.maxint);
print(-sys.maxint-1);

#浮点数的范围
print(sys.float_info);
print(sys.long_info);

5-13

def translate():
    time_str = raw_input("Please input the time, like 14:15:
")
    sList = time_str.split(":")
    if 0<=int(sList[0])<=24 and 0<=int(sList[1])<=60:
        time = int(sList[0]) * 60 + int(sList[1])
        return time
    else:
        return "error time!"

5-15

def GCM(num1, num2):
    tempNum = abs(num1 - num2)
    if (num1 % tempNum) == (num2 % tempNum) == 0:
        return tempNum
    else:
        return GCM(num2, tempNum)
def LCM(num1, num2):
    tempNum = GCM(num1, num2)
    return num1 * num2 / tempNum

5-17

import random
while 1:  
    N1=random.randint(2,100)  
    N2=random.randint(1,100)  
    if N1>N2:  
        break  
print 'N1 is %d, N2 is %d' %(N1,N2)   
list1=[]  
for i in range(0,N1):  
    n=random.randint(0,2**31-1)  
    list1.append(n)      
print list1  
list2=random.sample(list1,N2)  
list2.sort()  
print list2