Python rewrite C language program 100 example -- Part6

''' [Program 41] Question: Learn how to use static variables to define static variables. 1. program Analysis: 2. program source code: ''' # python does not have this function. It can only be like this :) def varfunc (): var = 0 print 'var = % d' % var + = 1if _ name _ = '_ main _': for I in range (3 ): varfunc () # attribut of class # as an attribute of the class. class Static: StaticVar = 5 def varfunc (self): self. staticVar + = 1 print self. staticVarprint Static. staticVara = Static () for I in range (3):. varfunc ()

'''Question: Learn how to use auto to define variables. 1. program Analysis: 2. program source code: without the auto keyword, use the variable scope for example '''num = 2def autofunc (): num = 1 print 'internal block num = % d' % num + = 1for I in range (3 ): print 'the num = % d' % num + = 1 autofunc ()

''' [Program 43] Question: Learn another usage of static. 1. program Analysis: 2. program source code: There is a static variable usage, python does not exist, demonstrate the use of a python scope method '''class Num: nNum = 1 def inc (self): self. nNum + = 1 print 'nnum = % d' % self. nNumif _ name _ = '_ main _': nNum = 2 inst = Num () for I in range (3 ): nNum + = 1 print 'the num = % d' % nNum inst. inc ()

''' [Program 45] Question: Learn How to Use register to define variables. 1. program Analysis: 2. program source code: without The register keyword, replace '''tmp = 0for I in range (1,101): tmp + = iprint 'the sum is % d' % tmp with an integer variable

''' [Program 46] Question: Macro # define command exercise (1) 1. program Analysis: 2. program source code: If there is no macro in C language, then '''true = 1 FALSE = 0def SQ (x) is written ): return x * xprint 'program will stop if input value less than 50. 'Again = 1 while again: num = int (raw_input ('Please input number') print 'the square for this number is % d' % (SQ (num )) if num> = 50: again = TRUE else: again = FALSE

'''Question: Macro # define command exercise (2) 1. program Analysis: 2. program source code: # include "stdio. h "# define exchange (a, B) {\/* The macro definition allows two clothes commands. In this case, you must add" \ "*/int t on the rightmost side; \ t = a; \ a = B; \ B = t; \} 'This macro-defined python does not support '''def exchange (a, B): a, B = B, a return (a, B) if _ name _ = '_ main _': x = 10 y = 20 print 'x = % d, y = % d' % (x, y) x, y = exchange (x, y) print 'X = % d, y = % d' % (x, y)

''' [Program 48] Question: Macro # define command exercise (3) 1. program Analysis: 2. program source code: # define LAG> # define SMA <# define EQ = # include "stdio. h "void main () {int I = 10; int j = 20; if (I LAG j) printf (" \ 40: % d larger than % d \ n ", i, j); else if (I EQ j) printf ("\ 40: % d equal to % d \ n", I, j); else if (I SMA j) printf ("\ 40: % d smaller than % d \ n", I, j); elseprintf ("\ 40: No such value. \ n ") ;}do not know how to use python to implement similar functions ''' if _ name _ = '_ main __': I = 10 j = 20 if I> j: print '% d larger than % d' % (I, j) elif I = j: print '% d equal to % d' % (I, j) elif I <j: print' % d smaller than % d' % (I, j) else: print 'no such value'

''' [Program 49] Question: # if # ifdef and # ifndef comprehensive application. 1. Program Analysis: 2. program source code: # include "stdio. h" # define MAX # define MAXIMUM (x, y) (x> y )? X: y # define MINIMUM (x, y) (x> y )? Y: xvoid main () {int a = 10, B = 20; # ifdef MAXprintf ("\ 40: The larger one is % d \ n", MAXIMUM (, b); # elseprintf ("\ 40: The lower one is % d \ n", MINIMUM (a, B); # endif # ifndef MINprintf ("\ 40: the lower one is % d \ n ", MINIMUM (a, B); # elseprintf (" \ 40: The larger one is % d \ n ", MAXIMUM (, b); # endif # undef MAX # ifdef MAXprintf ("\ 40: The larger one is % d \ n", MAXIMUM (a, B )); # elseprintf ("\ 40: The lower one is % d \ n", MINIMUM (a, B )); # Endif # define MIN # ifndef MINprintf ("\ 40: The lower one is % d \ n", MINIMUM (a, B); # elseprintf ("\ 40: the larger one is % d \ n ", MAXIMUM (a, B); # endif} is used for preprocessing. python does not support this mechanism to demonstrate lambda usage. '''Maximum = lambda x, y: (x> y) * x + (x <y) * yMINIMUM = lambda x, y: (x> y) * y + (x <y) * xif _ name _ = '_ main __': a = 10 B = 20 print 'the largar one is % d' % MAXIMUM (a, B) print 'the lower one is % d' % MINIMUM (a, B)