Add C++ program to find minimum number of swaps to sort an array

[simran-kaur5]

What does this PR do?

• Adds a C++ program to compute the minimum number of swaps required to sort an array.
• Implements a cycle detection approach to count swaps efficiently.
• Includes comments and basic test in main() function.

Algorithm Used

• Paired values with original indices
• Sorted the pairs by value
• Detected cycles to count minimum swaps needed

Sample Test Case

Input:
{6, 7, 8, 1, 2, 3, 9, 12}
Output:
3 (Minimum swaps)

[realstealthninja]

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