认识Python 程序 #calculate the area of triangle ''' step 1: input three sides stpe 2: apply the area formula step 3: print out the result ''' import math a=6 b=4 c=5 s=(a+b+c)/2. area=math. sqrt(s*(s-a)*(s-b)*(s-c)) print "area= " , area Python编程基础 注释 导入math模块
Python 保留字 Python编程基础 and elif import raise as else in return assert except is try break finally lambda while class for not with continue from or def global pass del if print
③ 描述算法 —— 用程序描述 应用案例 for Cock in range(100): for Hen in range(100): for Chick in range(100): if Cock+Hen+Chick==100 and 5*Cock+3* Hen + Chick /3==100: print "Cock: %3 d" %Cock, "Hen: %3 d" %Hen, "Chick: %3 d" %Chick Cock: 0 Hen: 25 Chick: 75 Cock: 3 Hen: 20 Chick: 77 Cock: 4 Hen: 18 Chick: 78 Cock: 7 Hen: 13 Chick: 80 Cock: 8 Hen: 11 Chick: 81 Cock: 11 Hen: 6 Chick: 83 Cock: 12 Hen: 4 Chick: 84 �束条件又限定 Chick能被 3整除�
④调试与运行——算法改进及优化 应用案例 for Cock in range(100): for Hen in range(100): for Chick in range(100): if Cock+Hen+Chick==100 and 5*Cock+3* Hen + Chick /3==100 and Chick%3==0: print "Cock: %3 d" %Cock, "Hen: %3 d" %Hen, "Chick: %3 d" %Chick Cock: 0 Hen: 25 Chick: 75 Cock: 4 Hen: 18 Chick: 78 Cock: 8 Hen: 11 Chick: 81 Cock: 12 Hen: 4 Chick: 84
④调试与运行——算法优化 应用案例 for Cock in range(20): for Hen in range(34): 改进算法 Chick=100 -Cock-Hen if Chick%3==0 and 5*Cock+3* Hen + Chick /3==100: print "Cock: %3 d" %Cock, "Hen: %3 d" %Hen, "Chick: %3 d" %Chick