Recursive DP URAL 1586 threeprime Numbers

Topic Portal

1 /*2 Test instructions: n digits, any consecutive three-digit number is a prime number, so how many n digits3 Optimal substructure: Consider a 3-digit number, which can be enumerated, the 4th and 3rd digits, and the 2nd digit determines whether the number is prime4 So, Dp[i][j][k] represents the I-digit, the highest digit J, the second high digit K5 State transfer equation: dp[i][j][k] + = Dp[i-1][k][l]6 Note: The highest bit is enumerated starting from 1:)7 Detailed Explanation:http://blog.csdn.net/zhangyanxing666/article/details/96285638 */9#include <cstdio>Ten#include <iostream> One#include <algorithm> A#include <cstring> -#include <cmath> - using namespacestd; the  - Const intMAXN = 1e4 +Ten; - Const intINF =0x3f3f3f3f; - Const intMOD = 1e9 +9; + intprime[ One][ One][ One]; - intvis[1010]; + intdp[maxn][ One][ One]; A  at voidSolvevoid) - { -memset (Prime,0,sizeof(prime)); -memset (Vis,0,sizeof(Vis)); -Memset (DP,0,sizeof(DP)); -      for(intI=2; i<= +; ++i) in     { -         if(!Vis[i]) to         { +Vis[i] =true; -              for(intj=i*2; j<= +; j+=i) the             { *VIS[J] =true; $             }Panax Notoginsengprime[i/ -][i/Ten%Ten][i%Ten] =1; -         } the     } +  A      for(intI=1; i<=9; ++i) the     { +          for(intj=0; j<=9; ++j) -         { $              for(intk=0; k<=9; ++K)if(Prime[i][j][k]) dp[3][i][j]++; $         }  -     } -  the      for(intI=4; i<=10000; ++i) -     {Wuyi          for(intj=1; j<=9; ++j) the         { -              for(intk=0; k<=9; ++k) Wu             { -                  for(intL=0; l<=9; ++l) About                     if(Prime[j][k][l]) dp[i][j][k] = (Dp[i][j][k] + dp[i-1][K][L])%MOD; $             } -         } -     } - } A  + intMainvoid)//URAL 1586 Threeprime Numbers the { -     //freopen ("m.in", "R", stdin); $  the solve (); the     intN; the      while(SCANF ("%d", &n) = =1) the     { -         intAns =0; in          for(intI=1; i<=9; ++i) the         { the              for(intj=0; j<=9; ++j) AboutAns = (ans + dp[n][i][j])%MOD; the         } the  theprintf ("%d\n", ans); +     } -  the     return 0;Bayi}

Recursive DP URAL 1586 threeprime Numbers