Write a program to find Minimum and Maximum numbers from the given array using Recursion.

min_max_recursion.c

#include <stdio.h>

// Recursive function to find maximum
int findMax(int arr[], int n) {
    if(n == 1) 
        return arr[0];   // base case
    
    int maxRest = findMax(arr, n - 1); // recursion on n-1 elements
    
    return (arr[n - 1] > maxRest) ? arr[n - 1] : maxRest;
}

// Recursive function to find minimum
int findMin(int arr[], int n) {
    if(n == 1) 
        return arr[0];   // base case
    
    int minRest = findMin(arr, n - 1); // recursion on n-1 elements
    
    return (arr[n - 1] < minRest) ? arr[n - 1] : minRest;
}

int main() {
    int n, i;
    printf("Enter size of array: ");
    scanf("%d", &n);

    int arr[n];
    printf("Enter %d elements: ", n);
    for(i = 0; i < n; i++) {
        scanf("%d", &arr[i]);
    }

    int max = findMax(arr, n);
    int min = findMin(arr, n);

    printf("Maximum element = %d\n", max);
    printf("Minimum element = %d\n", min);

    return 0;
}

✅ Step-by-Step Explanation

🔹 1. Input Array

• User enters array size and elements
• Example: arr = [5, 8, 2, 9, 1]

🔹 2. Recursive Max Function

int findMax(int arr[], int n) {
    if(n == 1) return arr[0];
    int maxRest = findMax(arr, n - 1);
    return (arr[n - 1] > maxRest) ? arr[n - 1] : maxRest;
}

• Base case: When only one element remains, return it
• Recursive case: Compare current element with max of remaining elements
• Example: For [5,8,2,9,1], compares 1 with max of [5,8,2,9], etc.

🔹 3. Recursive Min Function

int findMin(int arr[], int n) {
    if(n == 1) return arr[0];
    int minRest = findMin(arr, n - 1);
    return (arr[n - 1] < minRest) ? arr[n - 1] : minRest;
}

• Same logic as max function but compares for smaller values
• Example: For [5,8,2,9,1], compares 1 with min of [5,8,2,9], etc.

🔹 4. Result Output

• Prints the final minimum and maximum values
• Example output: Maximum = 9, Minimum = 1

🖨️ Example Run

Input:

Enter size of array: 5
Enter 5 elements: 5 8 2 9 1

Output:

Maximum element = 9
Minimum element = 1

📌 Key Concepts Covered

Recursion

Functions calling themselves with smaller subproblems

Base Case

Termination condition for recursive calls

Divide & Conquer

Breaking problem into smaller subproblems (n-1 elements)

Comparison Logic

Ternary operator used to compare elements

Array Processing

Handling array elements recursively