Investigation LightOJ - 1068

 1 #include<cstdio>
 2 #include<cstring>
 3 int ans[83][11][83][83];
 4 int a,b,k,T,TT;
 5 int w[12];
 6 int dp(int pos,int r,int sum,bool pre0,bool limit)
 7 {
 8     if(pos<1)    return r==0&&sum%k==0&&!pre0;
 9     if(!limit&&ans[k][pos][r][sum]!=-1)
10         return ans[k][pos][r][sum];
11     int i,end=limit?w[pos]:9,res=0;
12     for(i=0;i<=end;i++)
13         res+=dp(pos-1,(r*10+i)%k,sum+i,pre0&&i==0,limit&&i==w[pos]);
14     return limit?res:ans[k][pos][r][sum]=res;
15 }
16 int get(int x)
17 {
18     int g=0;
19     for(;x>0;x/=10)    w[++g]=x%10;
20     return dp(g,0,0,1,1);
21 }
22 int main()
23 {
24     memset(ans,-1,sizeof(ans));
25     scanf("%d",&T);
26     for(TT=1;TT<=T;TT++)
27     {
28         scanf("%d%d%d",&a,&b,&k);
29         if(k>82)
30         {
31             printf("Case %d: %d\n",TT,0);
32             continue;
33         }
34         printf("Case %d: %d\n",TT,get(b)-get(a-1));
35     }
36     return 0;
37 }