Print Decreasing

Faq

Q1) What is the time complexity?
ans: As n calls are made and work is done corresponding to these n calls therefore the time complexity becomes O(n).

Q2) What is the space complexity?
ans: Since no extra space is used, therefore space complexity is constant, however you should know that if the recursion call stack is taken into account, then space complexity will be O(n) as there are n recursive calls.

Q3) What is base condition?
ans: Since we are printing in decreasing order we are going to stop our recursive call when the n is 0.

Hints

Hint 1: Use the concept of Recursion  with base condition n=0.
Hint 2: Try to call the recursive call from n to n==0.
Hint 2: Beware of overflow.

Mcq

Q1) What will be the base condition?
    if (n == _ )
          return;
    
    a) 1
    b) 0
    c) -1
    d) 2

ans: b) 0

Q2) What will be the recursive call?

    printDecreasing(_____);
    
    a) n-2;
    b) n+1;
    c) n-1;
    d) n+2;
    
ans: c)n-1

Q3) what is the output if n==3?

    printDecreasing(int n) {
      if (n == 2)
        return;

      System.out.print(n + "\t");

      printDecreasing(n - 1);
    }
    
    a) 3 2 1
    b) 2 1
    c) 3
    d) 3 2 1 0
  
ans: c) 3