考虑线性的搜索会超时，所以用二叉搜索来解决，代码如下：
1 class TimeMap: 2 def __init__(self): 3 self.ST = dict() 4 5 def set(self, key: 'str', value: 'str', timestamp: 'int') -> 'None': 6 if key in self.ST.keys(): 7 D = self.ST[key]#dict 8 D.update({timestamp:value}) 9 self.ST.update({key:D}) 10 else: 11 D = dict() 12 D.update({timestamp:value}) 13 self.ST.update({key:D}) 14 15 16 def get(self, key: 'str', timestamp: 'int') -> 'str': 17 if key in self.ST.keys(): 18 D = self.ST[key] 19 V = self.binSearch(timestamp,D) 20 return V 21 else: 22 return '' 23 24 def binSearch(self,target,D): 25 times = list(D.keys()) 26 n = len(times) 27 minval = times[0] 28 maxval = times[-1] 29 if target < minval: 30 return '' 31 32 if target == minval: 33 return D[times[0]] 34 35 if target >= maxval: 36 return D[times[-1]] 37 38 left = 0 39 right = n - 1 40 while left < right: 41 mid = (left + right) // 2 42 if times[mid] == target: 43 return D[times[mid]] 44 elif times[mid]<target: 45 left = mid + 1 46 elif times[mid]>target: 47 right = mid - 1 48 if left == 0: 49 return D[times[left]] 50 else: 51 return D[times[left-1]]
但是这种写法会超时，这应该是代码质量问题，目前没明白是啥原因。
哪位博友知道我的代码的问题，欢迎告知。
参考了一下别人的方案，看到一个线性搜索的解决方案，却可以通过。
1 class TimeMap: 2 3 def __init__(self): 4 """ 5 Initialize your data structure here. 6 """ 7 self.dic = {} 8 9 def set(self, key: 'str', value: 'str', timestamp: 'int') -> 'None': 10 if key in self.dic: 11 self.dic[key].append({'v': value, 't': timestamp}) 12 else: 13 self.dic[key] = [{'v': value, 't': timestamp}] 14 15 def get(self, key: 'str', timestamp: 'int') -> 'str': 16 if key in self.dic: 17 for kv in reversed(self.dic[key]): 18 if timestamp >= kv['t']: 19 return kv['v'] 20 return "" 21 else: 22 return ""