1. import random
2. from collections import defaultdict
3.  
4.  
5. history = []
6. last_seen_4 = 0
7. last_seen_5 = 0
8. last_roll_not_feature = True
9.  
10. def get5star():
11.     #if the last 5 star is not promo, get promo
12.     global last_roll_not_feature
13.     if last_roll_not_feature:
14.         last_roll_not_feature = False
15.         return "featured"
16.  
17.     if random.random() < 0.5:
18.         last_roll_not_feature = False
19.         return "featured"
20.  
21.     else:
22.         last_roll_not_feature = True
23.         return "non-featured"
24.  
25.  
26.  
27. def gacha():
28.     global last_seen_5
29.     global last_seen_4
30.     GACHA = random.random()
31.  
32.     if GACHA <= 0.006 or last_seen_5 == 89:
33.         last_seen_5 = 0
34.         last_seen_4 = 0
35.         return get5star()
36.    
37.     elif GACHA <= 0.057 or last_seen_4 == 9:
38.         last_seen_4 = 0
39.         last_seen_5 += 1
40.         return "some 4 star character"
41.     else:
42.         last_seen_5 +=1
43.         last_seen_4 +=1
44.         return "nice 3 star sword"
45.  
46. history_5_star = defaultdict(int)
47. history_total = []
48.  
49. for i in range(10000):
50.     history = []
51.     total_pull = 0
52.     featured_count = 0
53.     while(featured_count < 1):
54.         PULL = gacha()
55.         total_pull += 1
56.         history += [PULL]
57.         if PULL == "featured":
58.             featured_count += 1
59.     history_total += [total_pull]
60.  
61.  
62.  
63.  
64. print("Average pulls required for C0 featured 5 star" ,sum(history_total)/len(history_total))