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C program to merge two arrays

C program to merge two arrays into another array. They are assumed to be sorted in ascending order. A user inputs them; the program combines them to get a larger array. If they aren't in ascending order, we can sort them and then use the merge function. Another method is to merge them first and then sort it. Sorting them first takes less time as compared to sorting a large array. Merging two sorted lists is used in the merge sort algorithm.

C program to merge two sorted arrays

// It is assumed a user will enter arrays in ascending order
#include <stdio.h>

void merge(int [], int, int [], int, int []);

int main() {
  int a[100], b[100], m, n, c, sorted[200];

  printf("Input number of elements in first array\n");
  scanf("%d", &m);

  printf("Input %d integers\n", m);
  for (c = 0; c < m; c++) {
    scanf("%d", &a[c]);
  }

  printf("Input number of elements in second array\n");
  scanf("%d", &n);

  printf("Input %d integers\n", n);
  for (c = 0; c < n; c++) {
    scanf("%d", &b[c]);
  }

  merge(a, m, b, n, sorted);

  printf("Sorted array:\n");

  for (c = 0; c < m + n; c++) {
    printf("%d\n", sorted[c]);
  }

  return 0;
}

void merge(int a[], int m, int b[], int n, int sorted[]) {
  int i, j, k;

  j = k = 0;

  for (i = 0; i < m + n;) {
    if (j < m && k < n) {
      if (a[j] < b[k]) {
        sorted[i] = a[j];
        j++;
      }
      else {
        sorted[i] = b[k];
        k++;
      }
      i++;
    }
    else if (j == m) {
      for (; i < m + n;) {
        sorted[i] = b[k];
        k++;
        i++;
      }
    }
    else {
      for (; i < m + n;) {
        sorted[i] = a[j];
        j++;
        i++;
      }
    }
  }
}

Download Merge arrays program.

Merge two arrays C program output:
Merge two arrays C program

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