Merge pull request #127 from verma-tanishq/tanishq

Adding interpolation search algorithm

searching/README.md

@@ -5,6 +5,7 @@
 1. [Linear Search](c-or-cpp/linear-search.cpp)
 2. [Binary Search](c-or-cpp/binary-search.cpp)
 3. [Jump Search](c-or-cpp/jump-search.cpp)
+4. [Interpolation Search](c-or-cpp/interpolation-search.cpp)
 
 ### Python
 

searching/c-or-cpp/interpolation-search.cpp

@@ -0,0 +1,59 @@
+// C++ program to implement interpolation search
+#include<bits/stdc++.h>
+using namespace std;
+
+// If x is present in arr[0..n-1], then returns
+// index of it, else returns -1.
+int interpolationSearch(int arr[], int n, int x)
+{
+	// Find indexes of two corners
+	int lo = 0, hi = (n - 1);
+
+	// Since array is sorted, an element present
+	// in array must be in range defined by corner
+	while (lo <= hi && x >= arr[lo] && x <= arr[hi])
+	{
+		if (lo == hi)
+		{
+			if (arr[lo] == x) return lo;
+			return -1;
+		}
+		// Probing the position with keeping
+		// uniform distribution in mind.
+		int pos = lo + (((double)(hi - lo) /
+			(arr[hi] - arr[lo])) * (x - arr[lo]));
+
+		// Condition of target found
+		if (arr[pos] == x)
+			return pos;
+
+		// If x is larger, x is in upper part
+		if (arr[pos] < x)
+			lo = pos + 1;
+
+		// If x is smaller, x is in the lower part
+		else
+			hi = pos - 1;
+	}
+	return -1;
+}
+
+// Driver Code
+int main()
+{
+	// Array of items on which search will
+	// be conducted.
+	int arr[] = {10, 12, 13, 16, 18, 19, 20, 21,
+				22, 23, 24, 33, 35, 42, 47};
+	int n = sizeof(arr)/sizeof(arr[0]);
+
+	int x = 18; // Element to be searched
+	int index = interpolationSearch(arr, n, x);
+
+	// If element was found
+	if (index != -1)
+		cout << "Element found at index " << index;
+	else
+		cout << "Element not found.";
+	return 0;
+}