题目：原题链接（中等）
标签：字典树
| 解法 | 时间复杂度 | 空间复杂度 | 执行用时 |
|---|---|---|---|
| Ans 1 (Python) | O ( N × L ) O(N×L) O(N×L) | O ( N × L ) O(N×L) O(N×L) | 40ms (78.90%) |
| Ans 2 (Python) | |||
| Ans 3 (Python) |
解法一：
class MapSum:
def __init__(self):
self.trie = [0, {}]
self.count = {}
def insert(self, key: str, val: int) -> None:
if key in self.count:
val, self.count[key] = val - self.count[key], val
else:
self.count[key] = val
node = self.trie
for ch in key:
node[0] += val
if ch not in node[1]:
node[1][ch] = [0, {}]
node = node[1][ch]
node[0] += val
# print(self.trie)
def sum(self, prefix: str) -> int:
node = self.trie
for ch in prefix:
if ch not in node[1]:
return 0
node = node[1][ch]
return node[0]
