get range sum

To get the range sum in C++, you can use a loop to iterate through the range and accumulate the sum of the elements. Here's an example of how you can do this:

#include <iostream>
#include <vector>

int getRangeSum(const std::vector<int>& nums, int start, int end) {
    int sum = 0;
    for (int i = start; i <= end; i++) {
        sum += nums[i];
    }
    return sum;
}

int main() {
    std::vector<int> nums = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
    int start = 2;
    int end = 6;
    int rangeSum = getRangeSum(nums, start, end);
    std::cout << "The sum of the range from " << start << " to " << end << " is: " << rangeSum << std::endl;

    return 0;
}

Let's break down the steps involved:

1. First, we include the necessary headers, iostream for input/output operations and vector for using a dynamic array-like structure.

2. We define a function called getRangeSum that takes a vector of integers (nums) and two integer parameters (start and end) representing the range.

3. Inside the getRangeSum function, we initialize a variable sum to 0. This variable will accumulate the sum of the elements in the range.

4. We use a for loop to iterate through the range from start to end. The loop variable i is initialized with start and the loop continues as long as i is less than or equal to end. In each iteration, we add the value at index i of nums to the sum variable.

5. After the loop, we return the calculated sum.

6. In the main function, we define a vector nums containing some sample numbers.

7. We also define the start and end variables to specify the range for which we want to calculate the sum.

8. We call the getRangeSum function with the nums, start, and end variables as arguments, and store the result in the rangeSum variable.

9. Finally, we print the result using cout and the << operator.

This code will output the sum of the range from 2 to 6, which in this case is 20.