# 303-range-sum-query-immutable


Try it on <a href='https://leetcode.com/problems/303-range-sum-query-immutable'>leetcode</a>

## Description
<div class="description">
<div><p>Given an integer array <code>nums</code>, handle multiple queries of the following type:</p>

<ol>
	<li>Calculate the <strong>sum</strong> of the elements of <code>nums</code> between indices <code>left</code> and <code>right</code> <strong>inclusive</strong> where <code>left &lt;= right</code>.</li>
</ol>

<p>Implement the <code>NumArray</code> class:</p>

<ul>
	<li><code>NumArray(int[] nums)</code> Initializes the object with the integer array <code>nums</code>.</li>
	<li><code>int sumRange(int left, int right)</code> Returns the <strong>sum</strong> of the elements of <code>nums</code> between indices <code>left</code> and <code>right</code> <strong>inclusive</strong> (i.e. <code>nums[left] + nums[left + 1] + ... + nums[right]</code>).</li>
</ul>

<p>&nbsp;</p>
<p><strong>Example 1:</strong></p>

<pre><strong>Input</strong>
["NumArray", "sumRange", "sumRange", "sumRange"]
[[[-2, 0, 3, -5, 2, -1]], [0, 2], [2, 5], [0, 5]]
<strong>Output</strong>
[null, 1, -1, -3]

<strong>Explanation</strong>
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
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= nums.length &lt;= 10<sup>4</sup></code></li>
	<li><code>-10<sup>5</sup> &lt;= nums[i] &lt;= 10<sup>5</sup></code></li>
	<li><code>0 &lt;= left &lt;= right &lt; nums.length</code></li>
	<li>At most <code>10<sup>4</sup></code> calls will be made to <code>sumRange</code>.</li>
</ul>
</div>
</div>

## Solution(Python)
```Python
class NumArray:

    def __init__(self, nums: List[int]):
        self.presum = [0]+list(accumulate(nums))

    def sumRange(self, left: int, right: int) -> int:
        return self.presum[right+1] - self.presum[left]


# Your NumArray object will be instantiated and called as such:
# obj = NumArray(nums)
# param_1 = obj.sumRange(left,right)
```