In-place convert matrix in specific order
Write a code to convert a matrix in specific way without using extra space.
Input: 1 2 3 4 5 6 7 8 9 Output: 1 6 7 2 5 8 3 4 9
At first look, the problem seems similar to finding transpose of the matrix. But if you look carefully, you will notice that every even column in output matrix has elements of corresponding row in input matrix in opposite order.
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The problem can be easily converted to transpose of the matrix by doing some modification to the input matrix. If we invert every even row present in input matrix, we can use solution given here to convert the matrix in desired order and that too without using any auxiliary memory.
Below is C++ implementation of the idea.
Given Matrix: 1 2 3 4 5 6 7 8 9 10 11 12 Transformed Matrix: 1 8 9 2 7 10 3 6 11 4 5 12
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