# Leetcode: Range Sum Query – Mutable

Range Sum Query – Mutable Similar Problems:

Related Reading: Segment Tree by geeksforgeeks.org

Given an integer array nums, find the sum of the elements between indices i and j (i <= j), inclusive.

The update(i, val) function modifies nums by updating the element at index i to val.

```Example:
Given nums = [1, 3, 5]

sumRange(0, 2) -> 9
update(1, 2)
sumRange(0, 2) -> 8
```

Note:

• The array is only modifiable by the update function.
• You may assume the number of calls to update and sumRange function is distributed evenly.
```What if, update and sumRange function is not distributed evenly?

Let's say, the ratio of update_count/sumRange_count is 10000 or 0.0001?
```

Github: code.dennyzhang.com

Credits To: leetcode.com

Leave me comments, if you have better ways to solve.

```## Blog link: https://code.dennyzhang.com/range-sum-query-mutable
class NumArray(object):

def __init__(self, nums):
"""
:type nums: List[int]
"""

def update(self, i, val):
"""
:type i: int
:type val: int
:rtype: void
"""

def sumRange(self, i, j):
"""
:type i: int
:type j: int
:rtype: int
"""

# Your NumArray object will be instantiated and called as such:
# obj = NumArray(nums)
# obj.update(i,val)
# param_2 = obj.sumRange(i,j)
```

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