Print Decreasing

 Input: 

5

Output:

5

4

3

2

1

package jan27;

public class PrintDecreasing {
    public static void main(String[] args) {
        int n = 5;
        printDecreasing(n);
    }

    /**
     * Prints numbers from n down to 1 using recursion.
     * <p>
     * Time Complexity: O(n)
     * - Each recursive call processes one value of n and makes a single recursive call,
     * resulting in n calls until the base case (n == 0) is reached.
     * <p>
     * Space Complexity: O(n)
     * - The call stack holds n function calls (from n to 1) before unwinding,
     * so space used is proportional to the depth of recursion.
     */
    private static void printDecreasing(int n) {
        if (n == 0) // base case
            return;

        System.out.println(n);   // work
        printDecreasing(n - 1);  // recursive call (faith)
    }
}

✅ Time and Space Complexity Table

Case	Time Complexity	Space Complexity	Explanation
Best	O(n)	O(n)	Function calls from n down to 1; recursion depth = n
Average	O(n)	O(n)	All recursive calls executed once; linear stack usage
Worst	O(n)	O(n)	In all cases, recursion proceeds to base case (n == 0)