On Thu, 09 Sep 2010 18:26:52 -0400, Dave Angel <da...@ieee.org> wrote:
> On 2:59 PM, Baba wrote: >> Hi >> >> In below code "the outer loop test in step 4 will execute ( n + 1 ) >> times (note that an extra step is required to terminate the for loop, >> hence n + 1 and not n executions), which will consume T4( n + 1 ) >> time." (from http://en.wikipedia.org/wiki/Analysis_of_algorithms) >> >> 1 get a positive integer from input >> 2 if n> 10 >> 3 print "This might take a while..." >> 4 for i = 1 to n >> 5 for j = 1 to i >> 6 print i * j >> 7 print "Done!" >> >> Why does step 4 execute n+1 times? what is the exta step mentioned >> above >> >> tnx >> Baba >> >Why are you posting a question about BASIC syntax in a Python forum? >Python has no such statement, and its close approximations work much >differently. > >If you really want an abstract answer, then you should be decomposing >those BASIC statements into smaller atoms. The for statement is >composed of at least three "atoms", one of which is probably executed >n+1 times. > >A BASIC for statement for i=1 to n >decomposes into approximately: > >4a, i = 1 >4b compare i to n >4c skip if greater > 5, 6 do some stuff >4d increment i REM And the vuitally important: 4e GOTO 4b But, as Robert noted, this is undoubtedly "pseudocode" rather than BASIC. Pity it's not Python-oriented pseudocode... >Note that the increment happens after steps 5 and 6, but it's part of line 4 > >Also note that the exact details depend thoroughly on the brand and >version of BASIC, there being at least 60 versions out there. For >example, I can think of at least three cases for what i will equal on >line 7. > >Incidentally, in some versions of BASIC, 4b and 4c might come after 4d, >and only be executed n times. > >DaveA -- http://mail.python.org/mailman/listinfo/python-list
