Recursive binary search in sorted array c++ -

i have write recursive function searches through sorted array.

#include <iostream> using namespace std;  int find(int value, int* folge, int max) {  }   int main() {     int const n = 7;     int wert1 = 4, wert2 = 13, wert3 = 2, wert4 = 25;     int folge[n] = {3,4,9,13,13,17,22};     wert1 = find(wert1, folge, n); } 

this part of code given , have finish it.
know how if have 4 variables available. (min , max) have three, there way edit start point of array given next function?

the function can written following way

#include <iostream>  int find( int value, int* folge, int max )  {     if ( max == 0 ) return -1;      int middle = max / 2;      if ( folge[middle] == value ) return middle;      bool lower = value < folge[middle];     int n = lower ? find( value, folge, middle )                    : find( value, folge + middle + 1, max - middle - 1 );      return n != -1 && !lower ? n + middle + 1: n;  }  int main() {     int const n = 7;     int wert1 = 4, wert2 = 13, wert3 = 2, wert4 = 25;     int folge[n] = {3,4,9,13,13,17,22};      std::cout << wert1 << " = " << find(wert1, folge, n) << std::endl;     std::cout << wert2 << " = " << find(wert2, folge, n) << std::endl;     std::cout << wert3 << " = " << find(wert3, folge, n) << std::endl;     std::cout << wert4 << " = " << find(wert4, folge, n) << std::endl;      return 0; } 

the program output is

4 = 1 13 = 3 2 = -1 25 = -1 

or 1 more test program

#include <iostream>  int find( int value, int* folge, int max )  {     if ( max == 0 ) return -1;      int middle = max / 2;      if ( folge[middle] == value ) return middle;      bool lower = value < folge[middle];     int n = lower ? find( value, folge, middle )                                    : find( value, folge + middle + 1, max - middle - 1 );      return n != -1 && !lower ? n + middle + 1: n;  }  int main() {     int const n = 7;     int folge[n] = {3,4,9,13,13,17,22};      ( int x : { 2, 3, 4, 9, 13, 17, 22, 25 } )     {         std::cout << x << " -> " << find( x , folge, n ) << std::endl;       }              return 0; } 

its output is

2 -> -1 3 -> 0 4 -> 1 9 -> 2 13 -> 3 17 -> 5 22 -> 6 25 -> -1