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C program to merge two sorted array



C program to merge two sorted array

Write a C program to read elements in two array and merge elements of two array into third array. Elements of array can be merged either in ascending order or in descending order.

/* C program to merge two sorted array in ascending order */

#include <stdio.h>
#define maxsize 100 //Maximum size of the array

int main()
{
    int array1[maxsize], array2[maxsize], mergeArray[maxsize];
    int size1, size2, mergeSize;
    int index1, index2, mergeIndex;
    int j;
     
    /* Input size of the array */
    printf("Enter the size of first array : ");
    scanf("%d", &size1);

    /* Input elements in the array */
    printf("Enter elements in first array : ");
    for(j=0; j<size1; j++)
    {
        scanf("%d", &array1[j]);
    }
     
    /* Input size of second array */
    printf("\nEnter the size of second array : ");
    scanf("%d", &size2);

    /* Input elements in second array */
    printf("Enter elements in second array : ");
    for(j=0; j<size2; j++)
    {
        scanf("%d", &array2[j]);
    }

    mergeSize = size1 + size2;
     
    /* Merge two array in ascending order      */
    index1 = 0;
    index2 = 0;
    for(mergeIndex=0; mergeIndex < mergeSize; mergeIndex++)
    {
        /* 
         * If all elements of one array 
         * is merged to final array
         */
        if(index1 >= size1 || index2 >= size2)
        {
            break;
        }

        if(array1[index1] < array2[index2])
        {
            mergeArray[mergeIndex] = array1[index1];
            index1++;
        }
        else
        {
            mergeArray[mergeIndex] = array2[index2];
            index2++;
        }
    }

    /* Merge the remaining elements of array     */
    while(index1 < size1)
    {
        mergeArray[mergeIndex] = array1[index1];
        mergeIndex++;
        index1++;
    }
    while(index2 < size2)
    {
        mergeArray[mergeIndex] = array2[index2];
        mergeIndex++;
        index2++;
    }

    /*  Print merged array     */
    printf("\nArray merged in ascending order : ");
    for(j=0; j<mergeSize; j++)
    {
        printf("%d\t", mergeArray[j]);
    }

    return 0;
}