// Main function
public static void Main(string[] args)
{
int[] freq = new int[] { 2, 1, 1, 3, 2, 3, 4, 5, 6, 7, 8, 9 };
int n = freq.Length;
BinaryIndexedTree tree = new BinaryIndexedTree();
// Build fenwick tree from given array
tree.constructBITree(freq, n);
Console.WriteLine("Sum of elements in arr[0..5]" + " is = " + tree.getSum(5));
freq[3] += 6;
updateBIT(n, 3, 6);
// Find sum after the value is updated
Console.WriteLine("Sum of elements in arr[0..5]" + " after update is = " + tree.getSum(5));
}
// Driver code
public static void Main(String [] args)
{
Console.WriteLine("Enter the number of elements .");
int n = int.Parse(Console.ReadLine());
int [] freq = new int[n];
for (i = 0; i < n; i++)
{
freq[i] = int.Parse(Console.ReadLine());
}
BinaryIndexedTree tree = new BinaryIndexedTree();
// Build fenwick tree from given array
tree.constructBITree(freq, n);
Console.WriteLine("Sum of elements in arr[0..5]" +
" is " + tree.getSum(5));
// Let use test the update operation
freq[3] += 6;
// Update BIT for above change in arr[]
updateBIT(n, 3, 6);
// Find sum after the value is updated
Console.WriteLine("Sum of elements in arr[0..5]" +
" after update is " + tree.getSum(5));
//Sample input and output.
int [] freq = { 5, 1, 0, 3, 2, 1, 4, 2, 6, 4, 8, 9 };
int n = freq.Length;
BinaryIndexedTree tree = new BinaryIndexedTree();
// Building fenwick tree from given array
tree.constructBITree(freq, n);
Console.WriteLine("Sum of elements in arr[0..5]" + " is " + tree.getSum(5));
freq[3] += 6;
// Update BIT for above change in arr[]
updateBIT(n, 3, 6);
Console.WriteLine("Sum of elements in arr[0...5]" + "is" + "after update is " + tree.getSum(5));
}