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307. Range Sum Query - Mutable (Medium)

Given an array nums and two types of queries where you should update the value of an index in the array, and retrieve the sum of a range in the array.

Implement the NumArray class:

• NumArray(int[] nums) initializes the object with the integer array nums.
• void update(int index, int val) updates the value of nums[index] to be val.
• int sumRange(int left, int right) returns the sum of the subarray nums[left, right] (i.e., nums[left] + nums[left + 1], ..., nums[right]).

 

Example 1:

Input
["NumArray", "sumRange", "update", "sumRange"]
[[[1, 3, 5]], [0, 2], [1, 2], [0, 2]]
Output
[null, 9, null, 8]

Explanation
NumArray numArray = new NumArray([1, 3, 5]);
numArray.sumRange(0, 2); // return 9 = sum([1,3,5])
numArray.update(1, 2);   // nums = [1,2,5]
numArray.sumRange(0, 2); // return 8 = sum([1,2,5])

 

Constraints:

• 1 <= nums.length <= 3 * 104
• -100 <= nums[i] <= 100
• 0 <= index < nums.length
• -100 <= val <= 100
• 0 <= left <= right < nums.length
• At most 3 * 104 calls will be made to update and sumRange.

Related Topics

[Binary Indexed Tree] [Segment Tree]

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