ural 1217. Unlucky Tickets

 1 #include <cstdio>
 2 #include <cstring>
 3 #include <cstdlib>
 4 #include <cmath>
 5 #include <deque>
 6 #include <vector>
 7 #include <queue>
 8 #include <iostream>
 9 #include <algorithm>
10 #include <map>
11 #include <set>
12 #include <ctime>
13 using namespace std;
14 typedef long long LL;
15 typedef double DB;
16 #define For(i, s, t) for(int i = (s); i <= (t); i++)
17 #define Ford(i, s, t) for(int i = (s); i >= (t); i--)
18 #define Rep(i, t) for(int i = (0); i < (t); i++)
19 #define Repn(i, t) for(int i = ((t)-1); i >= (0); i--)
20 #define rep(i, x, t) for(int i = (x); i < (t); i++)
21 #define MIT (2147483647)
22 #define INF (1000000001)
23 #define MLL (1000000000000000001LL)
24 #define sz(x) ((int) (x).size())
25 #define clr(x, y) memset(x, y, sizeof(x))
26 #define puf push_front
27 #define pub push_back
28 #define pof pop_front
29 #define pob pop_back
30 #define ft first
31 #define sd second
32 #define mk make_pair
33 inline void SetIO(string Name) {
34     string Input = Name+".in",
35     Output = Name+".out";
36     freopen(Input.c_str(), "r", stdin),
37     freopen(Output.c_str(), "w", stdout);
38 }
39 
40 inline int Getint() {
41     int Ret = 0;
42     char Ch = ‘ ‘;
43     while(!(Ch >= ‘0‘ && Ch <= ‘9‘)) Ch = getchar();
44     while(Ch >= ‘0‘ && Ch <= ‘9‘) {
45         Ret = Ret*10+Ch-‘0‘;
46         Ch = getchar();
47     }
48     return Ret;
49 }
50 
51 const int N = 25, M = 190;
52 int n;
53 LL Dp[N][M][M*2];
54 
55 inline void Input() {
56     scanf("%d", &n);
57 }
58 
59 inline void Solve() {
60     int m = n*9+1, Left, Right;
61     Left = n/2+1, Right = n/2;
62     Dp[0][0][m] = 1;
63     Rep(i, n+1)
64         Rep(j, m)
65             Rep(k, m*2)
66                 if(Dp[i][j][k]) {
67                     int x = k-m, _j, y;
68                     Rep(l, 10) {
69                         if(i+1 >= Left && l > j) break;
70                         if(i+1 <= Right) _j = j+l;
71                         else if(i+1 >= Left) _j = j-l;
72                         if((i+1)&1) y = x+l;
73                         else y = x-l;
74                         //printf("%d %d %d %d %d %d\n", i, j, k-m,i+1, _j, y);
75                         Dp[i+1][_j][y+m] += Dp[i][j][k];
76                     }
77                     //printf("%d %d %d %d\n", i, j, k-m, Dp[i][j][k]);
78                 }
79     
80     cout<<Dp[n][0][m]<<endl;
81 }
82 
83 int main() {
84     #ifndef ONLINE_JUDGE 
85     SetIO("B");
86     #endif 
87     Input();
88     Solve();
89     return 0;
90 }