URAL 1353 Milliard Vasya's Function DP

 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 
 4 int s;
 5 int dp[11][83];
 6 int cnt[83];
 7 void pre()  {
 8     memset( dp, 0, sizeof(dp) );
 9     memset( cnt, 0, sizeof(cnt) );
10     for( int j=1; j<=9; j++ ) dp[1][j] = 1;
11     for( int i=2; i<10; i++ )
12         for( int j=1; j<82; j++ )   
13             for( int k=j; k>0&&j-k<10; k-- )
14                 dp[i][j] += dp[i-1][k]; 
15     cnt[1] = 10;
16     for( int i=2; i<82; i++ )
17         for( int j=1; j<10; j++ )
18             cnt[i] += dp[j][i];
19 
20 }
21 
22 int main()  {
23     pre();
24     while( ~scanf("%d", &s ) )   {
25         printf("%d\n", cnt[s] );
26     }
27     return 0;
28 }