Java Data Structure How to - Use Merge sort to merge two arrays into a third sorted array

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Question

We would like to know how to use Merge sort to merge two arrays into a third sorted array.

Answer

public class MainClass {
  public static void main(String[] args) {
    int[] arrayA = { 23, 47, 81, 95 };
    int[] arrayB = { 7, 14, 39, 55, 62, 74 };
    int[] arrayC = new int[10];
/*w  w w . ja va 2 s  .c o  m*/
    merge(arrayA, arrayA.length, arrayB, arrayB.length, arrayC);
    for (int i : arrayC) {
      System.out.println(i);

    }
  }

  public static void merge(int[] arrayA, int sizeA, int[] arrayB, int sizeB, int[] arrayC) {
    int arrayAIndex = 0, arrayBIndex = 0, arrayCIndex = 0;

    while (arrayAIndex < sizeA && arrayBIndex < sizeB)
      if (arrayA[arrayAIndex] < arrayB[arrayBIndex])
        arrayC[arrayCIndex++] = arrayA[arrayAIndex++];
      else
        arrayC[arrayCIndex++] = arrayB[arrayBIndex++];

    while (arrayAIndex < sizeA)
      arrayC[arrayCIndex++] = arrayA[arrayAIndex++];

    while (arrayBIndex < sizeB)
      arrayC[arrayCIndex++] = arrayB[arrayBIndex++];
  }
}

The code above generates the following result.

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