コード例 #1
0
        //Contains the interpolation search algorithm
        public static void InterpolationSearch(float[] array, float toFind, int low, int high)
        {
            int boundaryCode = 0;

            int mid = 0;

            while (low <= high && toFind >= array[low] && toFind <= array[high])
            {
                //The midpoint of the array is found by estimating where the value being searched for should lie within the array, assuming equal distribution
                mid = (int)Math.Round(low + (((double)(high - low) / (array[high] - array[low])) * (toFind - array[low])));

                //If the value at the midpoint is equal to the value being searched for, tell the user and find other instances of the value
                if (array[mid] == toFind)
                {
                    Console.WriteLine("Value {0} found at index {1}", toFind, mid);
                    GenericSearchingAlgorithms.FindOtherInstances(array, toFind, mid);
                }

                //If the value at the midpoint is less than the value being searched for, change the low index so that the left side of the array is effectively discarded
                if (array[mid] < toFind)
                {
                    low = mid + 1;
                }
                //Otherwise, discard the right side of the array
                else
                {
                    high = mid - 1;
                }

                iterations++;
            }

            //If the value is not found in the array at all, tell the user and get the closest value in the array
            if (array[mid] != toFind)
            {
                Console.WriteLine("Value {0} not found in dataset. ", toFind);
                boundaryCode = -1;
                GenericSearchingAlgorithms.GetClosestValue(array, mid, toFind, boundaryCode);
            }
            else if (toFind > array[array.Length - 1])
            {
                boundaryCode = 1;
                GenericSearchingAlgorithms.GetClosestValue(array, mid, toFind, boundaryCode);
            }
            else if (toFind < array[0])
            {
                boundaryCode = 0;
                GenericSearchingAlgorithms.GetClosestValue(array, mid, toFind, boundaryCode);
            }
        }
コード例 #2
0
        //Contains the binary search algorithm
        public static void BinarySearch(float[] array, float toFind, int left, int right)
        {
            int boundaryCode = 0;

            //If the value is not out of range of the array, but it is not found in the array, find the closest value using boundary code -1
            if (left > right)
            {
                boundaryCode = -1;
                GenericSearchingAlgorithms.GetClosestValue(array, left - 1, toFind, boundaryCode);
                return;
            }

            //If the value being searched for is less than the leftmost value in the array, find the closest value using boundary code 0
            if (toFind < left)
            {
                boundaryCode = 0;
                GenericSearchingAlgorithms.GetClosestValue(array, left, toFind, boundaryCode);
                return;
            }
            //If the value being searched for is greater than the rightmost value in the array, find the closest value using boundary code 1
            else if (toFind > right)
            {
                boundaryCode = 1;
                GenericSearchingAlgorithms.GetClosestValue(array, right, toFind, boundaryCode);
                return;
            }

            //The midpoint between the current left and right indexes are found (initially set to 0, and the length of the array - 1)
            int mid = (int)Math.Floor((double)right + left / 2);

            //If the value is found at the midpoint, tell the user and find any other instances
            if (toFind == array[mid])
            {
                Console.WriteLine("\nValue {0} found at index {1}. ", toFind, mid);
                GenericSearchingAlgorithms.FindOtherInstances(array, toFind, mid);
            }
            //If the value being searched for is less than the midpoint, 'discard' the right side of the array and perform a binary search on the left side
            else if (toFind < array[mid])
            {
                BinarySearch(array, toFind, left, mid - 1);
            }
            //If the value being searched for is greater than the midpoint, 'discard' the left side of the array and perform a binary search on the right side
            else
            {
                BinarySearch(array, toFind, mid + 1, right);
            }

            iterations++;
        }