308. Range Sum Query 2D - Mutable

題目： Given a 2D matrix matrix, find the sum of the elements inside the rectangle defined by its uppe ...

315. Count of Smaller Numbers After Self

題目： You are given an integer array nums and you have to return a new counts array. The counts array ...

307. Range Sum Query - Mutable

題目: Given an integer array nums, find the sum of the elements between indices i and j (i ≤ j), incl ...