Question

O BJP3 Self-Check 12.14: mystery5 Language/Type: 血Java recursion recursive tracing Whitaker Brand (on 2013/04/01) Author: For each call to the following method, indicate what value is returned public int mystery5(int x, int y) if(x<0) { } else if (y<) } else if (x && y j else t -mystery$(-х, у); return return -mystery5(x, -y); 0) { return 0; return 100 * mystery5(x / 10, y / 10) + 10 * (x % 10) + y % 10; mysterys (5, 7) mystery5(12, 9) mystery5(-7, 4) mystery5(-23, -48) mystery5(128, 343) 57 1829 -74 2438 132483 Submit

these are right answer but i dont know how to do it, can u explain mystery5(12,9) and mystery5(128,343)

Answer 1

mystery5(x=12, y=9)
        => As x and y both are greater than 0, last if else block is hit.
        => 100 * mystery5(1, 0) + 10 * 2 + 9
        
Now mystery5(1, 0)
        => As x is greater than 0, hence again last if-else block is hit.
        => 100 * mystery5(0, 0) + 10 * 1 + 0
        => 100 * 0 + 10 + 0 = 10
        
So, mystery5(12, 9) =
        => 100 * 10 + 10 * 2 + 9 = 1000 + 20 + 9 = 1029.
        
=======================================

Similarly:
mystery5(128,343)
        => 100 * mystery5(12, 34) + 10 * 8 + 3

mystery5(12, 34)
        => 100 * mystery5(1, 3) + 10 * 2 + 4
        
mystery5(1, 3)
        => 100 * mystery5(0, 0) + 10 * 1 + 3
        => 100 * 0 + 10 + 3 = 13

So, now, mystery5(12, 34) => 100 * 13 + 10 * 2 + 4 = 1324
So, now, mystery5(128, 343) => 100 * 1324 + 10 * 8 + 3 = 132483

please upvote as i explained very clearly.