Number pattern double verticle pyramids

1        1
12      21
123    321
1234  4321
1234554321

#include<stdio.h>

int main()
{
int i,j,k;
for(i=1;i<=5;i++)
{
for(j=1;j<=5;j++)
{
if(j<=i)
printf("%d",j);
else
printf(" ");
}
for(j=5;j>=1;j--)
{
if(j<=i)
printf("%d",j);
else
printf(" ");
}
printf("\n");
}
return 0;
}