#677

Map Sum Pairs

specialist · 765 · lc medium +31 · 57.1% accepted · 1,732 likes · top 52%

Description

Design a key-value store that supports prefix-based sum queries.

Implement the MapSum class:

- MapSum() Creates the MapSum object.

- void insert(String key, int val) Associates key with val. If key already exists, its value is updated.

- int sum(string prefix) Returns the sum of all values whose corresponding key begins with prefix.

Example 1:

Input

["MapSum", "insert", "sum", "insert", "sum"]

[[], ["apple", 3], ["ap"], ["app", 2], ["ap"]]

Output

[null, null, 3, null, 5]

Example 2:

Explanation

MapSum mapSum = new MapSum();

mapSum.insert("apple", 3);

mapSum.sum("ap"); // return 3 (apple = 3)

mapSum.insert("app", 2);

mapSum.sum("ap"); // return 5 (apple + app = 3 + 2 = 5)

Code

class MapSum:

    def __init__(self):
        

    def insert(self, key: str, val: int) -> None:
        

    def sum(self, prefix: str) -> int:
        


# Your MapSum object will be instantiated and called as such:
# obj = MapSum()
# obj.insert(key,val)
# param_2 = obj.sum(prefix)

class MapSum:

    def __init__(self):
        

    def insert(self, key: str, val: int) -> None:
        

    def sum(self, prefix: str) -> int:
        


# Your MapSum object will be instantiated and called as such:
# obj = MapSum()
# obj.insert(key,val)
# param_2 = obj.sum(prefix)