Python的一些简单示例

1、球场领先多少分在多久的剩余时间里是安全的？

points = int(input("please input the leading points\n"))
has_ball = input("the leading team has ball (yes/no)\n")
second = int(input("please input the remaining seconds\n"))

points -= 3

if(has_ball == 'yes'):
    points += 0.5
else:
    points -= 0.5

if(points < 0):
    points = 0

points **= 2

if(points > second):
    print("safe")
else:
    print("not safe")

2、循环求一元二次方程的根

import math

ch=''

while(ch != 'q'):

    a = int(input("please input a\n"))
    b = int(input("please input b\n"))
    c = int(input("please input c\n"))

    if(a!=0):
        delt=b**2-4*a*c
        if(delt < 0):
            print("no solution!!!")
        elif(delt == 0):
            print("the result of the function is ",-b/(2*a))
        else:
            print("the two root of the function is ",(-b+math.sqrt(delt))/(2*a),"and",(-b-math.sqrt(delt))/(2*a))
    ch = input("quit?\n")

3、用break来修改2程序。

import math

while(True):

    a = int(input("please input a\n"))
    b = int(input("please input b\n"))
    c = int(input("please input c\n"))

    if(a!=0):
        delt=b**2-4*a*c
        if(delt < 0):
            print("no solution!!!")
        elif(delt == 0):
            print("the result of the function is ",-b/(2*a))
        else:
            print("the two root of the function is ",(-b+math.sqrt(delt))/(2*a),"and",(-b-math.sqrt(delt))/(2*a))
    ch=input("please input 'q' to stop the program or any key to continue\n")
    if(ch == 'q'):
        break

4、求常数e

#求常数e的值:e=1+1/1!+1/2!.....+1/n!

import math

e = 1
for i in range(0,15):
    e = e + 1.0/math.factorial(i)

print (e)

5、将4做修改

#求常数e的值:e=1+1/1!+1/2!.....+1/n!
e = 1
factorial = 1

for i in range(1,15):
    factorial = factorial * i
    e = e + 1.0/factorial

print (e)

6、求常数pi的值

pi = 0

for i in range(1,100000):
    pi = pi + (-1.0)**(i+1)/(2*i-1)

pi *= 4

print(pi)

7、考拉兹猜想：对于一个正整数，如果它是奇数，则对它乘以3并且加一，如果它是偶数则对它除以2，如此循环，最终都能够得到1

a = int(input("please input a number\n"))

while (a!=1):
    if(a%2 == 0):
        a = a / 2
    else:
        a = a*3+1
    print(a)

8、乘法表

for i in range(1,10):
    for j in range(1,10):
        print("%4d" % (i*j),end='')
    print("\n")

输出结果：
   1   2   3   4   5   6   7   8   9

   2   4   6   8  10  12  14  16  18

   3   6   9  12  15  18  21  24  27

   4   8  12  16  20  24  28  32  36

   5  10  15  20  25  30  35  40  45

   6  12  18  24  30  36  42  48  54

   7  14  21  28  35  42  49  56  63

   8  16  24  32  40  48  56  64  72

   9  18  27  36  45  54  63  72  81

9、今有雉兔同笼，上有35头，下有94足，问雉兔各几何？（穷举法）

for chicken in range(36):
    for rabbits in range(36):
        if chicken+rabbits == 35 and 2*chicken+4*rabbits == 94:
            print("the number of chicken is:",chicken," and the number of rabbits is:",rabbits)

10、二分法求平方根

a = float(input("please input a num\n"))

low = 0.0
high = a
guess = (low + high)/2

while(abs(guess**2 - a) > 1e-4):
    if(guess**2 > a):
        high = guess
    else:
        low = guess
    guess = (low + high)/2

print(guess)

但是这个程序是有问题的，当a小于1，或者a为负值的时候，则死循环