You are playing the following Bulls and Cows game with your friend: You write down a number and ask your friend to guess what the number is. Each time your friend makes a guess, you provide a hint that indicates how many digits in said guess match your secret number exactly in both digit and position (called "bulls") and how many digits match the secret number but locate in the wrong position (called "cows"). Your friend will use successive guesses and hints to eventually derive the secret number.

Write a function to return a hint according to the secret number and friend's guess, use A to indicate the bulls and B to indicate the cows. 

Please note that both secret number and friend's guess may contain duplicate digits.

Example 1:


Input: secret = "1807", guess = "7810"

Output: "1A3B"

Explanation: 1 bull and 3 cows. The bull is 8, the cows are 0, 1 and 7.

Example 2:


Input: secret = "1123", guess = "0111"

Output: "1A1B"

Explanation: The 1st 1 in friend's guess is a bull, the 2nd or 3rd 1 is a cow.

Note: You may assume that the secret number and your friend's guess only contain digits, and their lengths are always equal.

Difficulty: interview

Starter code:

class Solution:
    def getHint(self, secret: str, guess: str) -> str:
        

Solutions:
class Solution:
     def getHint(self, secret, guess):
         """
         :type secret: str
         :type guess: str
         :rtype: str
         """
         s_count = collections.defaultdict(int)
         g_count = collections.defaultdict(int)
         bull_cnt = 0
         # first iteration can get bull_cnt immediately
         for s, g in zip(secret, guess):
             if s == g: bull_cnt += 1
             # keep two counters for non matching chars    
             else:
                 s_count[s] += 1
                 g_count[g] += 1
         # if char in both s_count and g_count, the min of the two is the cow_cnt for this char        
         cow_cnt = sum(min(s_count[x], g_count[x]) for x in g_count if x in s_count)        
         return "{}A{}B".format(bull_cnt, cow_cnt)


class Solution:
     def getHint(self, secret, guess):
         """
         :type secret: str
         :type guess: str
         :rtype: str
         """
         secretDict={0:0,1:0,2:0,3:0,4:0,5:0,6:0,7:0,8:0,9:0}
         friendDict={0:0,1:0,2:0,3:0,4:0,5:0,6:0,7:0,8:0,9:0}
         bulls=0
         cows=0
         for s, g in zip(secret,guess):
             if s==g:
                 bulls+=1
             else:
                 secretDict[int(s)]+=1
                 friendDict[int(g)]+=1
         for i in range(10):
             cows+=min(secretDict[i],friendDict[i])
         return '{}A{}B'.format(bulls,cows)


class Solution:
     def getHint(self, secret, guess):
         """
         :type secret: str
         :type guess: str
         :rtype: str
         """
         need = {}
         seen = {}
         ret_A = 0
         ret_B = 0
         for i in range(len(secret)):
             if secret[i] == guess[i]:
                 ret_A += 1
             else:
                 if seen.get(secret[i],0) > 0:
                     ret_B += 1
                     seen[secret[i]] -= 1
                 else:
                     need[secret[i]] = need.get(secret[i],0) + 1
                 if need.get(guess[i],0) > 0:
                     ret_B += 1
                     need[guess[i]] -= 1
                 else:
                     seen[guess[i]] = seen.get(guess[i],0) + 1
         return str(ret_A) + 'A' + str(ret_B) + 'B'


class Solution:
     def getHint(self, secret, guess):
         """
         :type secret: str
         :type guess: str
         :rtype: str
         """
         dict, A, B = {}, 0, 0
         
         dicthash = {}
         for i in secret:
             if i in dicthash:
                 dicthash[i] += 1
             else:
                 dicthash[i] = 1
         
         for i in guess:
             if i in dicthash:
                 B += 1
                 if dicthash[i] == 1:
                     del dicthash[i]
                 else:
                     dicthash[i] -= 1
             
         for i, char in enumerate(list(secret)):
             if char == guess[i]:
                 A += 1
                 B -= 1
         
         return "{}A{}B".format(A, B)

class Solution(object):
     def getHint(self, secret, guess):
         """
         :type secret: str
         :type guess: str
         :rtype: str
                 """
         d = {}
         bull, cow = 0,0
 
         for index,s in enumerate(secret):
             if guess[index] == s:
                 bull += 1
             else:
                 d[s] = d.get(s,0) + 1
 
         for index,s in enumerate(secret):
             if (guess[index] != s) & (d.get(guess[index],0) != 0):
         	    cow += 1
         	    d[guess[index]] -= 1
         	    
         return str(bull) + "A" + str(cow) + "B"

class Solution:
     def getHint(self, secret, guess):
         """
         :type secret: str
         :type guess: str
         :rtype: str
         """
         bulls = cows = 0
         hist = [0]*10
         for i in range(len(secret)):
             if secret[i] == guess[i]:
                 bulls += 1
             else:
                 hist[ord(secret[i])-ord('0')] += 1
                 if hist[ord(secret[i])-ord('0')] - 1 < 0:
                     cows += 1
                 hist[ord(guess[i])-ord('0')] -= 1   
                 if hist[ord(guess[i])-ord('0')] + 1 > 0:
                     cows += 1
         return str(bulls) + "A" + str(cows) + "B"


class Solution:
     def getHint(self, secret, guess):
         """
         :type secret: str
         :type guess: str
         :rtype: str
         """
         bull=0
         cow=0
         for i in range(len(secret)):
             if secret[i]==guess[i]:
                 bull+=1
                 secret=secret[:i]+'a'+secret[i+1:]
                 guess=guess[:i]+'b'+guess[i+1:]
         secret=''.join(sorted(secret))
         guess=''.join(sorted(guess))
         i=0
         j=0
         while i<len(guess) and j<len(guess) :
             if secret[i] == 'a':
                 break
             if guess[j] == 'b':
                 break
             if secret[i] == guess[j]:
                 cow+=1
                 i+=1
                 j+=1
                 continue
             if secret[i] < guess[j]:
                 i+=1
                 continue            
             if secret[i] > guess[j]:
                 j+=1
                 continue
         print((secret,guess))
         return str(bull)+'A'+str(cow)+'B'


class Solution:
     def getHint(self, secret, guess):
         """
         :type secret: str
         :type guess: str
         :rtype: str
         """
         
         d1 = {}
         d2 = {}
         for i,c in enumerate(secret):
             if c not in d1:
                 d1[c] = []
             d1[c].append(i)
         
         for i,c in enumerate(guess):
             if c not in d2:
                 d2[c] = []
             d2[c].append(i)
         
         bulls,cows = 0,0
         
         for k in d2:
             if k not in d1:
                 continue
             curBulls = curCows = 0
             posGuess = d2[k]
             posSecret = d1[k]
             for p in posGuess:
                 if p in posSecret:
                     curBulls += 1
             #print(curBulls)
             curCows = max(0,min(len(posGuess) - curBulls,len(posSecret) - curBulls))
             #print(curCows)
             bulls += curBulls
             cows += curCows
         return str(bulls) + 'A' + str(cows) + 'B'
                     
             


class Solution:
     def getHint(self, secret, guess):
         """
         :type secret: str
         :type guess: str
         :rtype: str
         """
         
         bulls = 0
         mismatch_chars = collections.defaultdict(int)
         
         for secret_char, guess_char in zip(secret, guess):
             if secret_char == guess_char:
                 bulls += 1
             else:
                 mismatch_chars[secret_char] += 1
         
         cows = 0
         for secret_char, guess_char in zip(secret, guess):
             if secret_char != guess_char and mismatch_chars[guess_char] > 0:
                 mismatch_chars[guess_char] -= 1
                 cows += 1
         
         return '%sA%sB' % (bulls, cows)