Bubble sort in C

#include <stdio.h>
int main()
{
  int s,temp,i,j,a[20];
	
	printf("Enter total no. of elements:");
	scanf("%d",&s);
	
	printf("Enter %d elements:",s);
	for(i=0;i<s;i++)
		scanf("%d",&a[i]);
	//Bubble Sort Alogrithm
	for(i=s-2;i>=0;i--)
	{
		for(j=0;j<=i;j++)
		{	
			if (a[j]>a[j+1])
			{
				temp = a[j];
				a[j] = a[j+1];
				a[j+1] = temp;
			}
		}		
	}
	
	printf("After sorting:\n");
	for (i=0;i<s;i++)
		printf(" %d ",a[i]);
	return 0;
}