#include<cstdio>
int main()
{
  short a[2000]={0},b[2000]={0},c[2000]={0};
  short g,i,j,m=1;
  int n,k;
  scanf("%i %i",&n,&k);
  a[0]=1; b[0]=k-1;
  for(i=2;i<=n;i++)
  {
    g=0;
    for(j=0;j<m;j++)
    {
     c[j]=a[j]+b[j];
     c[j]=c[j]*(k-1)+g;
     (c[j]>9)?g=c[j]/10,c[j]=c[j]%10:g=0;
     a[j]=b[j];
     b[j]=c[j];
    }
    (g!=0)?b[m++]=g:b[m]=g;
  }
  for(j=m-1;j>=0;j--)printf("%d",b[j]);
  return 0;
}

Can u pls explain me the concep of this problem. for wat we ve given the k value.?

congratulation for excellent code. The only suggestion. May be
(g!=0)?b[m++]=g:b[m]=g;
better to replace by
if(g) b[m++]=g;