Question

Help with solution using Python

Riffle def riffle(items, out True): Given a list of items that is guaranteed to contain an even number of elements (note that the integer zero is an even number), create and return a list produced by performing a perfect riffle to the items by interleaving the items of the two halves of the list in an alternating fashion When performing a perfect riffle, also known as the Faro shuffle, the list of items is split in two equal sized halves, either conceptually or in actuality. The first two elements of the result are then the first elements of those halves. The next two elements of the result are the second elements of those halves, followed by the third elements of those halves, and so on up to the last elements of those halves. The parameter out determines whether this function performs an out shuffle or an in shuffle, that is, from which half of the list the alternating card is taken first. items Expected result out True [1, 5, 2, 6, 3, 7, 4, 8] [1, 2, 3, 4, 5, 6, 7, 8] Fals [5, 1, 6, 2, 7, 3, 8, 4] [1, 2, 3, 4, s, 6, 7, 8] e True ['bob', 'jack' [*bob', 'jack' True ['bob','jack' Fals ['jack', 'bob'

test using

def riffle_generator(seed):

random.seed(seed)

for i in range(1000):

n = random.randint(0, 100)

items = [random.randint(0, 10**6) for j in range(2 * n)]

yield (items, True)

yield (items, False)

Answer 1

Solution:

import random

def genrate(items, isOut):
   middleIndex=len(items)/2
   riffledItems=[0]*len(items);
   j=0;
   for i in range(middleIndex): #indexes from 0 to lenght/2
       if(isOut):
           riffledItems[j]=items[i] #maintain a indexing paramenter j and assign values accordigly
           j=j+1
           riffledItems[j]=items[i+middleIndex] #for out riffling add len/2 value to i value for getting
           j=j+1
       else:
           riffledItems[j]=items[i+middleIndex] #if it is false, do the assignment in reverse order.
           j=j+1
           riffledItems[j]=items[i]
           j=j+1
   return riffledItems

def riffle_generator(seed):
   items=[]
   random.seed(seed)
   for i in range(1000):
       n = random.randint(0, 100)
       items = [random.randint(0, 10**6) for j in range(2 * n)]
   #items=[1,2,3,4,5,6] Un comment this for testing purpose
   print "out riffle",genrate (items, True)
   print "in riffle",genrate(items, False)

riffle_generator(2)

code refrence image:

fe py import random Eder genrate (items, isout): 3 middle Index -len (items)/2 riffledItems-[0]*len (items); i-0; for i in range (middle Index) #indexes from if (isout) riffledItems [j]-items [i] #maintain to lenghtt/2 indexing paramenter j and assign values accordigly riffledItems [j]-items [i+middle Index] #for out riffling addlen/2 value to i value for getting 1 2 j-j + 1 else: riffledItems [] - items [1+middleIndex] # if it is false, do the assignment in reverse order riffledItems []-items [i] j-+1 return riffledItems Edef riffle generator (seed): 20 2 1 items-[ 22 random.seed (seed) for i in range (1000) n random.randint (0, 100) items [random.randint (0, 106) forj in range (2 23 24 25 n) 1 #items1,2,3,4,5,6] n comment this for testing purpose 28 print "in riffle", genrate (items, False) 2 9 30 riffle_generator (2)

output:

output with sample array:

GC:Windows System32\cmd.exe D: \SEGG>python riffle.py out riffle [440085, 373745, 689175, 415013, 37441, 424687, 652176, 191435, 9e8615, 491103, 842602, 199525, 720609, 757105, 59372, 764013, 699737, 150136, 284225, 911210 , 111133 , 719380, 886847, 429311, 931091, 613399, 981159, 519, 858397, 238483, 877781, 508435, 880495, 514378, 695359, 878702, 4176, 728279, 236308, 740288, 175241, 931 096, 34050, 603227, 442345, 329837, 627132, 718812, 845909, 641402, 696702, 983599, 814182, 989973, 947138, 90882, 480562, 323253, 655278, 289372, 889471, 935742, 97400 484289, 572034, 320315, 588394, 357492, 232691, 161523, 752359, 732555, 292459, 325777, 330883, 738031, 632084, 20996, 481448, 549893, 947041, 642661, 7444, 580162, 323 865, 800446, 29636, 586726, 50390, 355733, 748726, 559097, 378007, 406366, 772518, 122393, 819474, 292434, 337061, 406899, 962181, 115642, 463681, 229855, 680600, 86723 567359, 186651, 208318, 987558, 988230, 216385, 936354, 224579, 701076, 918768, 792486, 298635, 929433, 158328, 668308, 118838, 83 1934, 937767, 123832, 605270, 831438 in riffle r373745 6o985 415013 689175. 42450 341 191435. 652176 4911e3. ga861C O525842682 75718es. 720699. 764013 59372 150136. 699737. 911210, 204225, 719380, 111133, 429311, 886847, 613399, 931091, 519, 981159, 238483, 858397, 5e8435, 877781, 514378, 880495, 878702, 695359, 728279, 4176, 740288, 236308, 931096, 1752 41, 603227, 34050, 329837, 442345, 718812, 627132, 641402, 845909, 983599, 696702, 989973, 814182, 90082, 947138, 323253, 480562, 289372, 655278, 935742, 889471, 244597 72034, 484289, 588394, 320315, 232691. 357492, 752359, 161523, 292459, 732555. 330883, 325777, 632084. 738031, 481448, 20996, 947041, 549893. 7444, 642661. 323865, 5801 62, 29636, 8e0446, 50390, 586726, 748726, 355733, 378007, 559097, 772518, 406366, 819474, 122393, 337061, 292434, 962181, 406899, 463681, 115642, 680600, 229855, 567359 , 86723 , 208318, 186651, 988230, 987558, 936354, 216385, 701076, 224579, 792486, 918768, 929433, 298635, 668308, 158328, 831934, 118838, 123832, 937767, 831438, 605270, 871551, 104971, 81680, 155761, 782538, 902802, 390355, 65514, 767659, 757458, 553240, 724055, 641867, 778332, 992069, 185984, 189069, 863337, 442560, 890438] D: \SEGG>

D:\SEGG>python riffle.py out riffle [1, 4, 2, 5, 3, 6] in riffle [4, 1, 5, 2, 6, 3] D:\SEGG>