public void GivenMinBinaryIndexedTreeWhenUpdateChangeValueThenIntervalUpdated()
{
var data = Enumerable.Range(1, 200).ToArray();
var tree = new BinaryIndexedTree <int>(data,
(a, b) => Math.Min(a, b),
(a, b) =>
{
if (a > b)
{
throw new Exception("Can only decrease value");
}
return(Math.Min(a, b));
},
int.MaxValue
);
for (int i = 0; i < data.Length; i++)
{
int min = int.MaxValue;
for (int j = i; j < data.Length; j++)
{
min = Math.Min(min, data[j]);
Assert.Equal(min, tree.GetOperationValueOnInterval(i, j));
}
}
}
public void GivenRandomSumBinaryIndexedTreeWhenUpdateValuesThenIntervalReturnsCorrectValues()
{
var rand = new Random();
var data = new uint[64];
for (int i = 0; i < data.Length; i++)
{
data[i] = (uint)rand.Next();
}
var tree = new BinaryIndexedTree <uint>(data, (a, b) => a + b, (a, b) => a - b);
for (int i = 0; i < data.Length; i++)
{
var elem = (uint)rand.Next();
data[i] = elem;
tree[i] = elem;
}
for (int i = 0; i < data.Length; i++)
{
uint sum = 0;
for (int j = i; j < data.Length; j++)
{
sum += data[j];
Assert.Equal(sum, tree.GetOperationValueOnInterval(i, j));
}
}
}
public void GivenBinaryIndexedTreeWithSelectorWhenCreateTreeThenNoException()
{
var tree = new BinaryIndexedTree <Stub, int>(new[] { new Stub()
{
A = 1, B = 1
}, new Stub()
{
A = 100, B = 2
} }, Plus, Minus, (x) => x.B);
Assert.Equal(3, tree.GetOperationValueOnInterval(0, 1));
}
public void GivenSumBinaryIndexedTreeWhenAskOperationOnIntervalThenReturnCorrectValues()
{
var data = Enumerable.Range(1, 200).ToArray();
var tree = new BinaryIndexedTree <int, int>(data, (a, b) => a + b, (a, b) => a - b, (x) => x);
for (int i = 0; i < data.Length; i++)
{
int sum = 0;
for (int j = i; j < data.Length; j++)
{
sum += data[j];
Assert.Equal(sum, tree.GetOperationValueOnInterval(i, j));
}
}
}
public void GivenSumBinaryIndexedTreeWhenUpdateChangeValueThenIntervalUpdated()
{
var data = Enumerable.Range(1, 200).ToArray();
var tree = new BinaryIndexedTree <int, int>(data, (a, b) => a + b, (a, b) => a - b, (x) => x);
data[10] = 100;
tree[10] = 100;
for (int i = 0; i < data.Length; i++)
{
int sum = 0;
for (int j = i; j < data.Length; j++)
{
sum += data[j];
Assert.Equal(sum, tree.GetOperationValueOnInterval(i, j));
}
}
}
public void GivenBinaryIndexedTreeWheTryIntervalOutsideOfRangeThenThrowException(int left, int right)
{
var tree = new BinaryIndexedTree <int>(new[] { 1, 2, 3, 4 }, Plus, Minus);
Assert.Throws <ArgumentOutOfRangeException>(() => tree.GetOperationValueOnInterval(left, right));
}
