i need to do a program in c - increment and decrement array

#include<stdio.h>
#include<conio.h>
void main()
{
int a[20],b[20],c[20],n,i,j;
clrscr();
printf("\n Enter the no of elemnts");
scanf("%d",&n);
printf("\n enter the array\t");
for(i=0;i<n;i++)
scanf("%d",&a[i]);
for(i=0;i<n;i++)
c[i]=a[i];
j=n;
check:
if((a[j-1]+1)<=9)
a[j-1]++;
else
{
a[j-1]=0;
j--;
goto check;
}
if(a[0]==0)
{
for(i=1,j=0;i<=n;i++,j++)
b[i]=a[j];
b[0]=1;
printf("result of incremnted array\t");
for(i=0;i<=n;i++)
printf("%d\t",b[i]);
}
else
{
printf("result of incremnted array\t");
for(i=0;i<n;i++)
printf("%d\t",a[i]);
}
j=n;
while(j>=0)
{
if(c[j-1]==0)
 {
if(c[j-2]==0)
j=j-1;
else
{
c[j-2]--;
c[j-1]=c[j-1]+10;
if(j!=n)
j=j+1;
}
 }
else
{
c[j-1]--;
j=-1;
}
}
printf("\n decremented array");
for(i=0;i<n;i++)
printf("%d\t",c[i]);
getch();
}