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.
```
class Solution(object):
def getHint(self, secret, guess):
"""
:type secret: str
:type guess: str
:rtype: str
"""
maps = {}
## 解题方案
> 思路 1
******- 时间复杂度: O(N)******- 空间复杂度: O(N)******
- bulls = secret与guess下标与数值均相同的数字个数
- cows = secret与guess中出现数字的公共部分 - bulls
```python
classSolution:
defgetHint(self,secret:str,guess:str)->str:
cnt=collections.defaultdict(int)
bulls,cows=set(),set()
foriinrange(len(secret)):
if secret[i] not in maps:
maps[secret[i]] = [i]
ifguess[i]==secret[i]:
bulls.add(i)
else:
maps[secret[i]].append(i)
mapg = {}
cnt[secret[i]]+=1
foriinrange(len(guess)):
if guess[i] not in mapg:
mapg[guess[i]] = [i]
else:
mapg[guess[i]].append(i)
print maps, mapg
a,b = 0,0
for key in maps.keys():
if key in mapg.keys():
common = list(set(mapg[key]) & set(maps[key]))
#check for bull
a += len(common)
mapg[key] = [item for item in mapg[key] if item not in common]
maps[key] = [item for item in maps[key] if item not in common]
b += min(len(maps[key]), len(mapg[key]))
return str(a) + 'A' + str(b) + 'B'
```
两种解法都.......
都这么短。。。。。
我Python还是用的不行啊
```
class Solution(object):
def getHint(self, secret, guess):
"""
:type secret: str
:type guess: str
:rtype: str
"""
bull = sum(map(operator.eq, secret, guess))
sa = collections.Counter(secret)
sb = collections.Counter(guess)
cow = sum((sa & sb).values()) - bull
return str(bull) + 'A' + str(cow) + 'B'
```
bull = secret与guess下标与数值均相同的数字个数
cow = secret与guess中出现数字的公共部分 - bull
来分析一下这个解法
```
def getHint(self, secret, guess):
bulls = sum(map(operator.eq, secret, guess))
both = sum(min(secret.count(x), guess.count(x)) for x in '0123456789')