HDU 3943 K-th Nya Number

K-th Nya Number

Time Limit: 1000ms

Memory Limit: 65536KB

This problem will be judged on HDU. Original ID: 3943
64-bit integer IO format: %I64d      Java class name: Main

Arcueid likes nya number very much.
A nya number is the number which
has exactly X fours and Y sevens(If X=2 and Y=3 , 172441277 and 47770142
are nya numbers.But 14777 is not a nya number ,because it has only 1
four).
Now, Arcueid wants to know the K-th nya number which is greater than P and not greater than Q.

Input

The first line contains a positive integer T (T<=100), indicates there are T test cases.
The second line contains 4 non-negative integers: P,Q,X and Y separated by spaces.
( 0<=X+Y<=20 , 0< P<=Q <2^63)
The third line contains an integer N(1<=N<=100).
Then here comes N queries.
Each of them contains an integer K_i (0<K_i <2^63).

Output

For each test case, display its case number and then print N lines.
For each query, output a line contains an integer number, representing the K_i-th nya number in (P,Q].
If there is no such number,please output "Nya!"(without the quotes).

Sample Input

1
38 400 1 1
10
1
2
3
4
5
6
7
8
9
10

Sample Output

Case #1:
47
74
147
174
247
274
347
374
Nya!
Nya!

Source

2011 Multi-University Training Contest 11 - Host by UESTC

 

解题：数位dp+二分

 #include <bits/stdc++.h>
 using namespace std;
 using LL = long long;
 const int maxn = ;
 LL dp[maxn][maxn][maxn];
 int bt[maxn],x,y;
 LL dfs(int len,int a,int b,bool flag){
     if(len == -) return a == x && y == b;
     if(!flag && dp[len][a][b] != -) return dp[len][a][b];
     int u = flag?bt[len]:;
     LL ans = ;
     for(int i = ; i <= u; ++i){
         if(i == ) ans += dfs(len-,a + ,b,flag&&i == u);
         else if(i == ) ans += dfs(len-,a,b + ,flag&&i==u);
         else ans += dfs(len-,a,b,flag&&i==u);
     }
     if(!flag) dp[len][a][b] = ans;
     return ans;
 }
 LL solve(LL x){
     int cnt = ;
     while(x){
         bt[cnt++] = x%;
         x /= ;
     }
     return dfs(cnt - ,,,true);
 }
 int main(){
     int kase,m,cs = ;
     scanf("%d",&kase);
     while(kase--){
         LL P,Q,K;
         scanf("%I64d%I64d%d%d",&P,&Q,&x,&y);
         memset(dp,-,sizeof dp);
         scanf("%d",&m);
         printf("Case #%d:\n",cs++);
         LL tmp = solve(P);
         while(m--){
             scanf("%I64d",&K);
             K += tmp;
             LL low = P + ,high = Q,ans = -;
             while(low <= high){
                 LL mid = (low + high)>>;
                 if(solve(mid) >= K){
                     ans = mid;
                     high = mid - ;
                 }else low = mid + ;
             }
             if(ans == -) puts("Nya!");
             else printf("%I64d\n",ans);
         }
     }
     return ;
 }