C language: optimized merge sort

#include <stdio.h>
void showArr(int arr[] , int length);
void mergeSort(int a[] , int alen , int b[] , int blen , int *temp);
int main()
{
    
	int a[5] = {
    1,3,5,7,9};
	int b[3] = {
    2,8,10};
	int temp[8];
	mergeSort(a,5,b,3,temp);
	printf(" The sequence after merging and sorting is ：\n");
	showArr(temp,8);
	return 0;
} 
void mergeSort(int a[] , int alen , int b[] , int blen , int *temp)
{
    
	int i , j , k;
	i = k = j = 0;
	while(i < alen && j < blen)
		temp[k++]=a[i]<b[j]?a[i++]:b[j++];
	while(i < alen)
		temp[k++] = a[i++];
	while(j < blen)
		temp[k++] = b[j++];
}
void showArr(int arr[] , int length)
{
    
	for(int i = 0 ; i < length ; i++){
    
		printf("%4d",arr[i]);
	}
	printf("\n");
}