TheAlgorithms-C-Plus-Plus/Search/Interpolation Search.cpp

#include<iostream>
int InterpolationSearch(int A[], int n, int x){
	      int low =0; 
	      int high =n-1;
          while (low<=high){
	          int mid = low + (((high-1)*(x-A[low]))/(A[high]-A[low]));
	          if(x==A[mid])
	          	return mid;         // Found x, return (exit)
	          else if (x<A[mid])
	          	high = mid -1;      // X lies before mid
	          else
	          	low = mid +1;      // x lies after mid
	       }
	       return -1 ;
}

int main(){
	int A[] = {2,4,5,7,13,14,15,23};
	int x=17;                                  
	int index = InterpolationSearch(A, 8, x);  // passed array A inside the InterpolationSearch function
	if(index!= -1)
		std::cout << "Number "<<x<<" is at "<<index ;
	else
		std::cout << "Number "<<x<<" not found" ;
}

// randomly set x bcoz array was defined by us , therefore not reasonable for asking input.
// We could have asked for input if array elements were inputed by the user.