+ 1

Int a=2, b=4, c; c=a+++++b/2+a℅2;

24th Jan 2025, 5:13 PM
smitarani subudhi
smitarani subudhi - avatar
12 odpowiedzi
24th Jan 2025, 5:19 PM
Ausgrindtube
Ausgrindtube - avatar
+ 2
smitarani subudhi Your obfuscated code runs into a problem with your string of plus signs. According to C and C++ standards, your code would have "undefined behaviour" due to multiple operators with side effects (++) acting on same variable within the expression. There is also the problem that your 5 plus signs can be interpreted in a variety of configurations of x++, ++x, and x+y operators leading to different results. One possible interpretation is c = ((a++)++)+(b/2)+(a%2); a = 4, b = 4, c = 2+2+0 = 4 Another interpretation might be c = a+(++(++(b/2)))+(a%2); a = 2, b = 4, c = 2+4+0 = 6 Yet another interpretation could be c = a+((++(++b))/2)+(a%2); a = 2, b = 6, c = 2+3+0 = 5
25th Jan 2025, 2:11 AM
Shardis Wolfe
+ 1
Solo Based off operator precedence, the first interpretation I listed is what most compilers would use. Since x++ operator has higher precedence than ++x or x+y. So without parenthesis to make clear, The compiler would try post-fix increment twice on a (since x++ operator evaluates left-to-right), and be left with single plus operator. Post-fix increments would not increment a until after c is evaluated. Hence evaluation as c = ((a++)++) + (b/2) + (a%2) c = 2 + (4/2) + (2%2) = 2 + 2 + 0 = 4 a = 2 + 1 + 1 = 4
25th Jan 2025, 11:34 AM
Shardis Wolfe
+ 1
According to python correct answer 4
26th Jan 2025, 3:34 PM
Shubham verma
Shubham verma - avatar
0
c = a++; c = c + ++b/2 + a%2; Or c = a++; c += ++b/2 + a%2;
25th Jan 2025, 9:50 AM
Solo
Solo - avatar
0
Solo In neither case would c start off as only a++. Assignment operator has one of lowest operator precedence. So value of c would not be evaluated until the very end.
25th Jan 2025, 10:12 AM
Shardis Wolfe
0
Shardis Wolfe, you misunderstood me. I did not demonstrate the order of execution of this expression, I showed a ready-made solution to this problem without warning about an undefinite expression...😎
25th Jan 2025, 10:56 AM
Solo
Solo - avatar
0
Shardis Wolfe, by the way, your interpretations are not correct.
25th Jan 2025, 11:12 AM
Solo
Solo - avatar
0
Shardis Wolfe, tell me, where did you get this opinion about the work of the compiler? If you are right, then it is logical to assume that your expression c = ((a++)++) + (b/2) + (a%2); the compiler will read it without errors. I doubt that's the case. Have you checked it?-)
25th Jan 2025, 11:54 AM
Solo
Solo - avatar
0
Solo c=((a++)++) + (b/2) + (a%2); is how compilers would apply the operator orders of precedence to c=a+++++b/2+a%2; Since x++ has higher precedence than ++x, compiler would keep trying to apply it. So 1st pass - c=(a++)+++b/2+a%2 2nd pass - c=((a++)++)+b/2+a%2 3rd pass - c=((a++)++)+(b/2)+a%2 4th pass - c=((a++)++)+(b/2)+(a%2) The reason it would evaluate as undefined behaviour instead of a consistent answer is not all compilers may guarantee that the side effect of the a++ increment will be evaluated after c is evaluated.
25th Jan 2025, 12:30 PM
Shardis Wolfe
0
Shardis Wolfe, are you a bot?-)
25th Jan 2025, 2:50 PM
Solo
Solo - avatar
0
Nope. Just someone who had too much free time last night 😔
25th Jan 2025, 2:56 PM
Shardis Wolfe