How to find smallest in an integer array recursively (C++ Tutorial)

Finding smallest in an integer array recursively

FindSamllestRecursive() finds the smallest in an integer array recursively and returns the smallest value. It takes 4 parameters:

arr takes the array.

i takes the index of the array.

size takes the size of the array.

smallest holds the smallest element of the array.

Code of FindSamllestRecursive()

int FindSamllestRecursive( int arr[] , int i , int size , int smallest )

{

      if ( i < size )

      {

            if ( arr[i] < smallest )

                  smallest = arr[i];

            return FindSamllestRecursive( arr , i + 1 , size, smallest );

      }

      return smallest;

}

Summary of FindSamllestRecursive()

FindSamllestRecursive() starts from the first index of the array and recursively calls itself until i becomes equal to or greater than the size of array, at each function call the current element is checked against the smallest element, if the current element at arr[i] is smaller than the element in the smallest variable, then the current element is saved in the smallest variable.

At each recursive function call, the current index i is incremented by 1.

At the end, value in the smallest variable is returned from the function.

Example (C++)

#include "stdafx.h"

#include "iostream"

#include "conio.h"

using namespace std;

int FindSamllestRecursive( int arr[] , int i , int size , int smallest )

{

      if ( i < size )

      {

            if ( arr[i] < smallest )

                  smallest = arr[i];

            return FindSamllestRecursive( arr , i + 1 , size, smallest );

      }

      return smallest;

}

int main()

{

      const int size1 = 10;

    int arr1[size1] = {10,20,30,40,50,60,60,70,80,90};

      cout << "Smallest in array1 : " << FindSamllestRecursive( arr1 , 1 , size1 , arr1[0] );      //    10

      cout << endl;

      const int size2 = 10;

      int arr2[size2] = {85,20,30,40,50,60,60,70,75,80};

      cout << "Smallest in array2 : " << FindSamllestRecursive( arr2 , 1 , size2 , arr2[0] );      //    20

      cout << endl;

    const int size3 = 10;

    int arr3[size3] = {1,2,3,4,5,6,7,8,9,0};

    cout << "Smallest in array3 : " << FindSamllestRecursive( arr3 , 1 , size3 , arr3[0] );      //    0

      cout << endl;

    const int size4 = 10;

    int arr4[size4] = {10,20,30,40,50,60,70,80,90,100};

    cout << "Smallest in array4 : " << FindSamllestRecursive( arr4 , 1 , size4 , arr4[0] );      //    10

      cout << endl;

    const int size5 = 10;

    int arr5[size5] = {5,10,15,20,25,30,35,40,45,50};

    cout << "Smallest in array5 : " << FindSamllestRecursive( arr5 , 1 , size5 , arr5[0] );      //    5

      cout << endl;

     

      _getche();

      return 0;

}

Output

Smallest in array1 : 10

Smallest in array2 : 20

Smallest in array3 : 0

Smallest in array4 : 10

Smallest in array5 : 5