题目：​​原题链接​​（中等）

标签：哈希表、二分查找

解法一：

class TimeMap:

    def __init__(self):
        self.hashmap_t = collections.defaultdict(list)
        self.hashmap_val = collections.defaultdict(dict)

    def set(self, key: str, value: str, timestamp: int) -> None:
        if timestamp not in self.hashmap_t[key]:
            bisect.insort_left(self.hashmap_t[key], timestamp)
        self.hashmap_val[key][timestamp] = value

    def get(self, key: str, timestamp: int) -> str:
        if len(self.hashmap_t[key]) > 0:
            i = bisect.bisect_left(self.hashmap_t[key], timestamp)
            if i >= len(self.hashmap_t[key]):
                i -= 1
            if self.hashmap_t[key][i] > timestamp:
                i -= 1
            # print(i, self.hashmap_t[key], timestamp)
            if i >= 0:
                return self.hashmap_val[key][self.hashmap_t[key][i]]
            else:
                return ""
        else:
            return ""