public int Search(ArrayReader reader, int target)
{
int left = 0;
int right = 1;
while (reader.Get(right) < target)
{
right *= 2;
}
while (left < right - 1)
{
int mid = left + (right - left) / 2;
if (target == reader.Get(mid))
{
return(mid);
}
if (target < reader.Get(mid))
{
right = mid - 1;
}
else
{
left = mid + 1;
}
}
if (target == reader.Get(left))
{
return(left);
}
if (target == reader.Get(right))
{
return(right);
}
return(-1);
}
public int Search(ArrayReader reader, int target)
{
int left = 0, right = 1;
while (reader.Get(right) < target)
{
left = right;
right <<= 1;
}
while (left <= right)
{
var mid = left + (right - left) / 2;
var value = reader.Get(mid);
if (value == target)
{
return(mid);
}
else if (value > target)
{
right = mid - 1;
}
else
{
left = mid + 1;
}
}
return(-1);
}
public int BruteForce(ArrayReader reader, int target)
{
int left = 0, right = 10000;
while (left <= right)
{
int mid = left + (right - left) / 2;
int element = reader.Get(mid);
if (element == Int32.MaxValue)
{
right = mid - 1;
continue;
}
if (element == target)
{
return(mid);
}
else if (element < target)
{
left = mid + 1;
}
else
{
right = mid - 1;
}
}
return(-1);
}
public static int Search(ArrayReader reader, int key)
{
// TODO: Write your code here
int tempEnd = 1;
int tempStart = 0;
while (reader.Get(tempEnd) < key)
{
tempStart = tempEnd;
tempEnd *= 2;
if (reader.Get(tempEnd) == key)
{
return(tempEnd);
}
}
return(BinarySearch(reader, key, tempStart, tempEnd));
}
public int Search(ArrayReader reader, int target)
{
int left = 0, right = 1;
while (reader.Get(right) < target)
{
left = right;
right *= 2;
}
// [-1, 0, 3, 5, 9, 12] target = 9
// l r
// l r
// l r
// l r
// To keep logarithmic time complexity, let's extend it twice as far.
// If the reader[right] < target, then we can ignore all left side of the "right" index and move the search boundary to the right.
while (left <= right)
{
int mid = left + (right - left) / 2;
int element = reader.Get(mid);
if (element == target)
{
return(mid);
}
else if (element < target)
{
left = mid + 1;
}
else
{
right = mid - 1;
}
}
return(-1);
}
private static int BinarySearch(ArrayReader reader, int key, int start, int end)
{
while (start <= end)
{
int mid = start + (end - start) / 2;
if (reader.Get(mid) == key)
{
return(mid);
}
if (reader.Get(mid) > key)
{
end = mid - 1;
}
else
{
start = mid + 1;
}
}
return(-1);
}