Find a loop invariant (I) for the following while loop with the post-condition {Q: S=1}, where...

Find a loop invariant (I) for the following while loop with the post-condition

{Q: S=1}, where S is an integer and the operator / represents an integer division.

Show your work step by step to receive full credit.

         while (S > 1) do
              S = S / 2;
         }

Solutions

Expert Solution

Loop invariant can be defined as a condition which will always be true. This property must be satisfied throughout every iteration of the loop.

We have the post-condition:

Q: S = 1

The given loop checks if the value of 'S' is greater than 1 or not. If it is true, then it divides 'S' by 2 and this process is repeated in every iteration. The while loop condition will fail when the value of 'S" is one or less. At that case, the value of 'S' will never be less than one as it is integer in nature. Loop invariant does not depend on the state of the iterative condition. It always remains true irrespective of the iterative condition which can be true or false.

The post-condition must be true after the execution of the while loop condition.

So, one loop invariant we can determine from the given relation is:

S > 1 [the while loop will be executed only when 'S' is greater than one, not equal to one]

Please comment in case of any doubt.
Please upvote if this helps.

venereology answered 5 months ago

Next > < Previous

Related Solutions

According to the loop invariant theorem, a valid loop invariant ?(?)I(n) must have the property that...

According to the loop invariant theorem, a valid loop invariant ?(?)I(n) must have the property that Select one: a. ?(?)=0I(n)=0 after a finite number of steps. b. After the loop, ?→?(?)P→I(N) where ?P is the postcondition. c. ?(0)→?I(0)→Q, where ?Q is the precondition. d. None of the other answers are correct

How many times will the following while loop iterate? int i = 1; while (i <...

How many times will the following while loop iterate? int i = 1; while (i < 5) { i = i + 1; System.out.println(“Hello!”); } Group of answer choices 4 0 5 It will iterate infinitely

(C++)Change the following loop to a while loop: int i; for (i=0; i<10; i++) { ...

(C++)Change the following loop to a while loop: int i; for (i=0; i<10; i++) { cout<<i<<endl; }

Why is an exit condition so important for a while loop?

Why is an exit condition so important for a while loop?a.An exit condition is not vital. A while loop works fine without one.b.So the programmer knows when it is okay to leave the room.c.If no exit condition is provided, while loops cannot continue beyond one iterationd.It allows the loop to end instead of running indefinitely.e.While loops are unstable, and must know how to exi

I have to use a sentinel while loop to complete the following task in a java...

I have to use a sentinel while loop to complete the following task in a java program, I want to see how this is executed so I can better understand how the sentinel while loop works. Thank you! Convert Lab 10 from a counter controlled WHILE loop to a sentinel WHILE loop. Do the following: Prompts the user to enter a grade or a -1 to quit. IF the user entered a -1 THEN Display a message that the User...

Study the following code with a while-loop and convert it to a for-loop (fill in the...

Study the following code with a while-loop and convert it to a for-loop (fill in the blanks). int i=4, result=1; while(i>1) { result *= i; i--; } The following for-loop performs the same functionality: int result=1; for (__________ i=4; i _________1;____________) { result *= i; }

Here is a traditional loop in C: while (A{i} == 0) A{i} = A{5} + A{i+3};...

Here is a traditional loop in C: while (A{i} == 0) A{i} = A{5} + A{i+3}; (NOTE: please consider braces {} here as usual square brackets for array index). Assume that i is stored in register $s1, and the base address of the array A is in $s2. Fill in the multiple blank spaces in the following MIPS program that is supposed to be compiled from the above C loop: loop: sll $t0, $s1, add $t0, $t0, lw $t1, 20($s2)...

1. Consumer 1’s demand function is q = 20 – p, while consumer 2’s demand function...

1. Consumer 1’s demand function is q = 20 – p, while consumer 2’s demand function is q = 12 – 2p. 1) Draw the individual demand curves of each of two consumers. 2) Draw the aggregate demand function of the two consumers (bold the curve in your graphs). You can either use the method we discussed in class by dividing p into several intervals, or a more direct way by adding up the curves (see textbook). No matter which...

Re-write following while loop into Java statements that use a Do-while loop. Your final code should...

Re-write following while loop into Java statements that use a Do-while loop. Your final code should result in the same output as the original code below. int total = 0; while(total<100) { System.out.println("you can still buy for"+(100-total)+"Dollars"); total=total+5; }

Consider the linear time invariant system described by the transfer function G(s) given below. Find the...

Consider the linear time invariant system described by the transfer function G(s) given below. Find the steady-state response of this system for two cases: G(s) = X(s)/F(s) = (s+2)/(3(s^2)+6s+24) when the input is f(t) = 5sin(2t) and f(t) = 5sin(2t) + 3sin(2sqrt(3)t)

Subjects