## Algorithm

Problem Name: 303. Range Sum Query - Immutable

Given an integer array `nums`, handle multiple queries of the following type:

1. Calculate the sum of the elements of `nums` between indices `left` and `right` inclusive where `left <= right`.

Implement the `NumArray` class:

• `NumArray(int[] nums)` Initializes the object with the integer array `nums`.
• `int sumRange(int left, int right)` Returns the sum of the elements of `nums` between indices `left` and `right` inclusive (i.e. `nums[left] + nums[left + 1] + ... + nums[right]`).

Example 1:

```Input
["NumArray", "sumRange", "sumRange", "sumRange"]
[[[-2, 0, 3, -5, 2, -1]], [0, 2], [2, 5], [0, 5]]
Output
[null, 1, -1, -3]

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
```

Constraints:

• `1 <= nums.length <= 104`
• `-105 <= nums[i] <= 105`
• `0 <= left <= right < nums.length`
• At most `104` calls will be made to `sumRange`.

## Code Examples

### #1 Code Example with C++ Programming

```Code - C++ Programming```

``````
class NumArray {
public:
NumArray(vector nums) {
int sum = 0;
for(auto x: nums){
sum += x;
dp.push_back(sum);
}
}

int sumRange(int i, int j) {
return i == 0 ? dp[j] : dp[j] - dp[i - 1];
}

private:
vectordp;
};
``````
Copy The Code &

Input

cmd
["NumArray", "sumRange", "sumRange", "sumRange"] [[[-2, 0, 3, -5, 2, -1]], [0, 2], [2, 5], [0, 5]]

Output

cmd
[null, 1, -1, -3]

### #2 Code Example with Java Programming

```Code - Java Programming```

``````
class NumArray {

int[] sumArray;

public NumArray(int[] nums) {
sumArray = new int[nums.length];
int currSum = 0;
for (int i = 0; i < nums.length; i++) {
currSum += nums[i];
sumArray[i] = currSum;
}
}

public int sumRange(int left, int right) {
return sumArray[right] - (left == 0 ? 0 : sumArray[left - 1]);
}
}
``````
Copy The Code &

Input

cmd
["NumArray", "sumRange", "sumRange", "sumRange"] [[[-2, 0, 3, -5, 2, -1]], [0, 2], [2, 5], [0, 5]]

Output

cmd
[null, 1, -1, -3]

### #3 Code Example with Python Programming

```Code - Python Programming```

``````
class NumArray:

def __init__(self, nums):
self.nums = nums
for i in range(1, len(nums)):
self.nums[i] += self.nums[i - 1]

def sumRange(self, i, j):
return self.nums[j] - self.nums[i - 1] if i else self.nums[j]
``````
Copy The Code &

Input

cmd
["NumArray", "sumRange", "sumRange", "sumRange"] [[[-2, 0, 3, -5, 2, -1]], [0, 2], [2, 5], [0, 5]]

Output

cmd
[null, 1, -1, -3]

### #4 Code Example with C# Programming

```Code - C# Programming```

``````
namespace LeetCode
{
public class _0303_RangeSumQueryImmutable
{
private readonly int[] sums;

public _0303_RangeSumQueryImmutable(int[] nums)
{
sums = new int[nums.Length];

var sum = 0;
for (int i = 0; i < nums.Length; i++)
{
sum += nums[i];
sums[i] = sum;
}
}

public int SumRange(int i, int j)
{
if (i == 0)
return sums[j];
else
return sums[j] - sums[i - 1];
}
}
``````
Copy The Code &

Input

cmd
["NumArray", "sumRange", "sumRange", "sumRange"] [[[-2, 0, 3, -5, 2, -1]], [0, 2], [2, 5], [0, 5]]

Output

cmd
[null, 1, -1, -3]