0002_百钱买鸡

百钱买鸡：公鸡5文钱一只，母鸡3文钱一只，小鸡3只一文钱，用100文钱买100只鸡，其中公鸡，母鸡，小鸡都必须要有，问公鸡，母鸡，小鸡要买多少只刚好凑足100文钱？

思路：设定公鸡，母鸡，小鸡各买x,y,z只，则满足下列条件：

　　　　x+y+z=100;

　　　　5x+3y+z/3=100；

 1 __author__ = ‘qq593‘
 2 # /usr/bin/python
 3 # -*- coding:utf-8 -*-
 4
 5 #x is the unknown number
 6 for y in range(1,33):
 7     for z in range(1,98):
 8         x =100-z-y
 9         if (0<x<20 and  x*5+y*3+z/3==100 and z%3==0):
10             print (x,y,z)
11 #z is the unknown number
12 for x in range(1, 20):
13     for y in range(1, 33):
14         z = 100 - x - y
15         if (z % 3 == 0) and (x * 5 + y * 3 + z / 3 == 100):
16             s = "gongji:%d;muji:%d;xiaoji:%d" % (x, y, z)
17             print (s)
18 #y is the unknown number
19 for x in range(1,20):
20     for z in range(98):
21         y=100-x-z
22         if (x*5+y*3+z/3==100 and z%3==0 and 0<y<33):
23             print (x,y,z)