(I am sorry, I badly speak on english)
I wish to show the a code of the decision of a problem 1036 (my solve is AC). For analysis of idea for beginners which cannot solve this problem.
Listing on C++:
#include <cstdio>
#include <vector>
using namespace std;
typedef vector<int> ss;
vector<ss> a(1001),b(1001);
vector<int> la(1001),lb(1001),st(1001),r(101),h(101);
int l,lr,lh,n,i,j,s,k,m;
void main()
{
for(i=0;i<1001;++i){a[i].resize(101);b[i].resize(101);}
scanf("%d%d",&n,&s);
if(s%2){printf("0");return;}
s/=2;
if (s/n >= 10) {printf("0"); return;}
if (s*2>n*9)s=n*9-s;
for(i=0;i<=s;++i)
   {
   if (i <= 9)a[i][1]=1;
   la[i]=1;
   }
la[0]=1;la[1]=1;
for(i=2;i<=n;++i)
   {
   b=a; lb=la;
   for(j=1;j<=s;++j)
      for(m=0;m<=j-1;++m)
         if (j-m <= 9)
              {
             for(k=1;k<=max(la[j],lb[m]);++k)
                   {
                   a[j][k]=a[j][k]+b[m][k];
                   a[j][k+1]=a[j][k+1]+a[j][k]/10;
                   a[j][k]=a[j][k]%10;
                  }
              while(a[j][la[j]+1])la[j]=la[j]+1;
            }
    }
lr=la[s];lh=la[s];
r=a[s];h=a[s];
for(j=lr;j>=1;--j)
   {
    for(k=lh;k>=2;--k)r[j+k-1]+=r[j]*h[k];
    r[j]=r[j]*h[1];
   }
l=0;
for(j=1;j<=lr+lh;++j)
   {
    l+=r[j];
    r[j]=l % 10;
    l=l / 10;
   }
if (r[lr+lh])lr+=lh;
else lr+=lh-1;
for(i=lr;i>=1;--i)printf("%d",r[i]);
}