Python的一些简单示例（2）

1、判断是否为素数

import mathx = 7for i in range(2,(int)(math.sqrt(x))+1):    if(x%i == 0):        print("x is not a sushu")        breakelse:    print("x is a sushu")//当for非正常结束则不执行else，如果for正常结束则执行else

2、依次打印50个素数

import mathcount = 0num = 2while(count < 50):    for i in range(2,(int)(math.sqrt(num))+1):        if(num%i == 0):            break    else:        print("%4d" % num,end=" ")        count += 1    num += 1

3、判断一个数是不是回文数

original = 12321num = originalresult = 0while(num != 0):    result = result*10 + num%10    num = int(num/10)if(original == result):    print("the num is a palin\n")else:    print("the num is not a palin\n")

4、判断一个数是不是回文素数。

import mathdef is_palin(num):    temp = num    result1 = 0    while(temp != 0):        result1 = result1*10 + temp%10        temp = int(temp/10)    if(num == result1):        return True    else:        return Falsedef is_parim(num):    for i in range(2,int(math.sqrt(num))+1):        if(num % i == 0):            return False            break    else:        return Truenum = 13131if(is_palin(num) and is_parim(num)):    print("ok")else:    print("no")

5、判断2033年的一月一号是星期几？【1800年1月1日是星期三，如果我可以得到从1800年1月1日到2033年1月1日的总天数，那么我用（3+total days）%7结果即是1800年1月1日是星期几】

def is_leap(year):    if((year%4 == 0 and year%100 != 0) or (year%400 == 0)) :        return True    else:        return Falsedef is_month_days(year,month):    if(month in (1,3,5,7,8,10,12)):        return 31    elif(month in (4,6,9,11)):        return 30    elif(is_leap(year)):        return 29    else:        return 28def is_total_days(year,month):    days = 0    for i in range(1800,year):        if(is_leap(i)):            days += 366        else:            days += 365    for j in range(1,month):        days += is_month_days(year,j)    return daysdef is_which_day(year,month):    return (3+is_total_days(year,month))%7year = 2033month = 12print(is_which_day(year,month))

6、斐波那契数

（非递归）

def unfib(n):    if(n==1 or n==2):        return 1    f1 = 1    f2 = 1    i = 2    while(i < n):        f3 = f1 + f2        f1 = f2        f2 = f3        i+=1    return f3print(unfib(6))

（递归）

def fib(n):    if(n==1 or n==2):        return 1    else:        return fib(n-1)+fib(n-2)print(fib(9))

7、随机停车问题

import randomdef parking(low,high):    if(high - low < 1):        return 0    else:        x = random.uniform(low,high-1)        return parking(low,x) + 1 + parking(x+1,high)print(parking(0,5))

8、汉诺塔问题

def hanoi(n,A,B,C):    if(n == 1):        print("move ",n," from ",A,"to ",C)    else:        hanoi(n-1,A,C,B)        print("move ",n," from ",A,"to ",C)        hanoi(n-1,B,A,C)hanoi(3,"left","mid","right")结果如下：       move  1  from  left to  rightmove  2  from  left to  midmove  1  from  right to  midmove  3  from  left to  rightmove  1  from  mid to  leftmove  2  from  mid to  rightmove  1  from  left to  right        

9、统计一个字符串中元音字母的个数

def vowle_count(s):    count = 0    for c in s:        if(c in ('a','e','i','o','u','A','E','I','O','U')):            count += 1    return countprint(vowle_count("hello world"))

10、判断文件中的哪些名字是回文数，并且将其打印出来

（非递归）

def parlindrom(s):    low = 0    high = len(s)-1    while(low < high):        if(s[low] != s[high]):            return False        low += 1        high -= 1    return Truef = open("test.txt","r")for line in f:    if(parlindrom(line.strip())):        print(line.strip())f.close()

（递归）

def parlindrom(s):    if(len(s) <= 1):            return True    else:        if(s[0] != s[-1]):            return False        else:            return parlindrom(s[1:-1])f = open("test.txt","r")for line in f:    if(parlindrom(line.strip())):        print(line.strip())f.close()