rsequentialsearch.cpp

datastucutre and algorithms, application, in C

// recursive sequential search

#include <iostream>
#include <algorithm> // has copy

using namespace std;


template<class T>
int rSequentialSearch(T a[], int n, const T& x)
{// Search the unordered list a[0:n-1] for x.
 // Return position if found; return -1 otherwise.
   if (n < 1) return -1;
   if (a[n-1] == x) return n - 1;
   return rSequentialSearch(a, n-1, x);
}

int main()
{
   int a[7] = {1, 5, 3, 4, 7, 2, 0};

   // output the array elements
   cout << "a[0:6] = ";
   copy(a, a+7, ostream_iterator<int>(cout, " "));
   cout << endl;

   // test the search function
   cout << "4 is at position " << rSequentialSearch(a, 7, 4) << endl;
   cout << "0 is at position " << rSequentialSearch(a, 7, 0) << endl;
   cout << "1 is at position " << rSequentialSearch(a, 7, 1) << endl;
   cout << "8 is at position " << rSequentialSearch(a, 7, 8) << endl;
   return 0;
}