Practice Range Sum Query - Immutable
Read the task, work through the examples, and check your approach against the constraints. Use the original LeetCode task for coding and submissions.
Problem Statement
NumArray(nums) stores a fixed integer array. sumRange(left, right) returns the sum from left through right, including both endpoints. The array does not change between calls. Practice approach: Precompute prefix[0] = 0 and prefix[i + 1] = prefix[i] + nums[i]. A query is prefix[right + 1] - prefix[left]. Preprocessing and storage are O(n), and each query is O(1). The extra leading zero avoids special-casing left = 0. Test negative totals, one-element ranges, and the entire array.
Source: Range Sum Query - Immutable on LeetCode. Use the original task for its coding environment and submissions.
Examples
# Example 1
["NumArray","sumRange","sumRange","sumRange"] [[[4,-2,7]],[0,1],[1,2],[2,2]]
[null,2,5,7]
The inclusive sums are 4 - 2 = 2, -2 + 7 = 5, and the single value 7.
Constraints
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