GATE CSE 1999 | Question: 2.24

Question

Consider the following $C$ function definition

int Trial (int a, int b, int c)
{
    if ((a>=b) && (c<b)) return b;
    else if (a>=b) return Trial(a, c, b);
    else return Trial(b, a, c);
}

The functional Trial:

• A. Finds the maximum of $a$, $b$, and $c$

• B. Finds the minimum of $a$, $b$, and $c$

• C. Finds the middle number of $a$, $b$, $c$

• D. None of the above

Comments

if ((a>=b) && (c<b))

missing in question.

Answer 1

$$\begin{array}{|l|l|l|l|} \hline \textbf{a} & \textbf{b} & \textbf{c} & \textbf{Return} \\\hline \text{1} &  \text{1} & \text{1} & \text{The final return statement is $c < b.$}\\&&&\text{ So, this never returns. } \\\hline \end{array}$$
Answer D.

Comments

when we will take a=b=c then this program will generate infinite loop (because of b>c condition,to make it finite it should be b>=c)...so option D ,,,is right one

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I hate these none of above kinda questions… there’s no fun at all in solving them! There’s a different level of excitement when you find the answer and it matches with one of the options. Feels like an achievement.

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@Arjun sir directly checkmate the question. 

Answer 2

$Trial (a,b,c)$ return the median element of the $\text{a , b and c}$ , but not middle element of $\text{a , b and c}$ , so answer is $(D).$

Comments

For 3 values on sorting them its hould be middle value, but for same input a=b=c its falling into infinite loop

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How it is returning median value can you justify using options?

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what is the meaning of median of a,b,c here?

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If we write a,b, c in a sorted order then the number at the middle position is called Median element.

e.g. we've 3 numbers - 3 ,2 ,4

sorted order - 2 3 4 (3 is median)

 

Answer 3

1)First of all,in first if statement parenthesis are not balanced .so it  is Syntax error. there is no option called "syntax error".if we forget the balancing parenthesis we can move further.
2)let consider example
Trail(7,2,6) return 6
Trail(5,4,9) return 5
So from example you can conclude that it dose not return maximum or minimum or middle of element. in another case if a=b=c ,it stuck in infinite loop. so answer is d) None of the above

Comments

If we try it for a=8, b=6, c=4

it is going to produce middle element for all three cases if we can shuffle the values accordingly to check every case.

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@santit I tried with Trial(10,11,12) with all three combination it is giving always 11 which is middle element, so why D option is correct??

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@mohit7891 coz u are taking only one possibility of  values they can be anything like $a=b=c$ or $a>=b<=c$ anything.. so u've to check for all possibilites