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An algorithm rearranges a sequence of numbers following a specific rule in each step. Following is an illustration of input and the subsequent steps of rearrangement.
Input: 98 31 06 72 63 59 36 12 84
Step 1: 98 31 36 72 63 59 06 12 84
Step 2: 84 31 36 72 63 59 06 12 98
Step 3: 84 31 36 63 72 59 06 12 98
Step 4: 84 31 12 63 72 59 06 36 98

Using the same rule, trace the steps for the following input sequence:
Input: 12 31 59 36 63 72 98 84 06
The sum of the numbers for the given sequence whose positions remain unaltered through all the steps as in the input is:

  1. A
    94
  2. B
    103
  3. C
    129
  4. D
    131

Solution & Step-by-step Explanation

The rearrangement rules based on the index swaps are:
* Step 1: Swap index 3 and index 7.
* Step 2: Swap index 1 and index 9.
* Step 3: Swap index 4 and index 5.
* Step 4: Swap index 3 and index 8.

Let's trace the given input across all steps step-by-step:



* Step 1 (Swap index 3 and 7):



* Step 2 (Swap index 1 and 9):



* Step 3 (Swap index 4 and 5):



* Step 4 (Swap index 3 and 8):



Now let's check which elements tracking positions to remained completely unchanged from Input through all four subsequent steps:

* Position 2 held the value consistently throughout.
* Position 6 held the value consistently throughout.
All other positions experienced a mutation in at least one step.

Practice this question

Try it yourself before checking the explanation above.

An algorithm rearranges a sequence of numbers following a specific rule in each step. Following is an illustration of input and the subsequent steps of rearrangement.
Input: 98 31 06 72 63 59 36 12 84
Step 1: 98 31 36 72 63 59 06 12 84
Step 2: 84 31 36 72 63 59 06 12 98
Step 3: 84 31 36 63 72 59 06 12 98
Step 4: 84 31 12 63 72 59 06 36 98

Using the same rule, trace the steps for the following input sequence:
Input: 12 31 59 36 63 72 98 84 06
The sum of the numbers for the given sequence whose positions remain unaltered through all the steps as in the input is:
A
94
B
103
C
129
D
131

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