题目：原题链接（中等）
标签：数组、设计
解法 | 时间复杂度 | 空间复杂度 | 执行用时 |
Ans 1 (Python) | 构造 = O ( L ) ; set = O ( 1 ) ; snap = O ( 1 ) ; get = O ( l o g N ) | O ( N ) | 684ms (13.58%) |
Ans 2 (Python) | |||
Ans 3 (Python) |
解法一：
class SnapshotArray:
def __init__(self, length: int):
self.lst = [[[0, 0]] for _ in range(length)]
self.now = 0
def set(self, index: int, val: int) -> None:
if self.lst[index][-1][0] == self.now:
self.lst[index][-1][1] = val
else:
self.lst[index].append([self.now, val])
def snap(self) -> int:
self.now += 1
return self.now - 1
def get(self, index: int, snap_id: int) -> int:
lst = self.lst[index]
l, r = 0, len(lst)
while l < r:
m = (l + r) // 2
if lst[m][0] <= snap_id:
l = m + 1
else:
r = m
return lst[l - 1][1]
