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53 lines
1.4 KiB
Plaintext
53 lines
1.4 KiB
Plaintext
---
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title: '303. Range Sum Query - Immutable'
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description: Given an integer array nums, handle multiple queries of the following type
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sidebar:
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label: 'Range Sum Query - Immutable'
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badge: 'Easy'
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---
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<Badge variant="accent">Prefix Sum</Badge>
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### Example 1:
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- Input: `["NumArray", "sumRange", "sumRange", "sumRange"]` `[[[-2, 0, 3, -5, 2, -1]], [0, 2], [2, 5], [0, 5]]`
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- Output: `[null, 1, -1, -3]`
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- Explanation: `NumArray numArray = new NumArray([-2, 0, 3, -5, 2, -1]);` `numArray.sumRange(0, 2); // return (-2) + 0 + 3 = 1` `numArray.sumRange(2, 5); // return 3 + (-5) + 2 + (-1) = -1` `numArray.sumRange(0, 5); // return (-2) + 0 + 3 + (-5) + 2 + (-1) = -3`
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### Constraints:
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- `1 <= nums.length <= 10^4`
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- `-10^5 <= nums[i] <= 10^5`
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- `0 <= left <= right < nums.length`
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- At most `10^4` calls will be made to `sumRange`.
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## Solution
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```js
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/**
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* @param {number[]} nums
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*/
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class NumArray {
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constructor(nums) {
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this.prefix = [0];
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for (let n of nums){
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this.prefix.push(this.prefix[this.prefix.length - 1] + n);
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}
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}
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/**
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* @param {number} left
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* @param {number} right
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* @return {number}
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*/
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sumRange(left, right) {
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return this.prefix[right + 1] - this.prefix[left];
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}
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}
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/**
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* Your NumArray object will be instantiated and called as such:
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* var obj = new NumArray(nums)
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* var param_1 = obj.sumRange(left,right)
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*/
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```
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