Question
Given 2 sorted arrays, A and B, where A is long enough to hold the contents of A and B, write a function to copy the contents of B into A without using any buffer or additional memory.
eg.
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A = {1,3,5,0,0,0} B = {2,4,6} mergeArrays(A, B) A = {1,2,3,4,5,6} |
Once you think that you’ve solved the problem, click below to see the solution.
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Solution
How was that problem? You can check out the solution in the video below.
Here is the source code for the solution shown in the video:
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public void mergeArrays(int[] a, int[] b, int aLength, int bLength) { if (aLength + bLength > a.length) throw new IllegalArgumentException(); int aIndex = aLength - 1; int bIndex = bLength - 1; int mergeIndex = aLength + bLength - 1; while (aIndex >= 0 && bIndex >= 0) { if (a[aIndex] > b[bIndex]) { a[mergeIndex] = a[aIndex]; aIndex--; } else { a[mergeIndex] = b[bIndex]; bIndex--; } mergeIndex--; } while (bIndex >= 0) { a[mergeIndex] = b[bIndex]; bIndex--; mergeIndex--; } } |
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