hdu3555 Bomb
与上一个类似，更简单一些，标记前面是否出现过49和4.
1 #include <iostream> 2 #include<cstdio> 3 #include<cstring> 4 #include<algorithm> 5 #include<stdlib.h> 6 #include<vector> 7 #include<cmath> 8 #include<queue> 9 #include<set> 10 using namespace std; 11 #define N 100000 12 #define LL long long 13 #define INF 0xfffffff 14 const double eps = 1e-8; 15 const double pi = acos(-1.0); 16 const double inf = ~0u>>2; 17 LL n,dp[22][2][2][2]; 18 int d[22]; 19 LL dfs(int i,bool e,bool o,bool p) 20 { 21 if(i==-1) 22 { 23 if(p) return 1; 24 return 0; 25 } 26 if(!e&&dp[i][e][o][p]!=-1) return dp[i][e][o][p]; 27 int j; 28 int mk = e?d[i]:9; 29 LL ans = 0; 30 for(j = 0; j <= mk ; j++) 31 { 32 if(p) 33 ans+=dfs(i-1,e&&j==mk,0,1); 34 else 35 { 36 if(o&&j==9) 37 ans+=dfs(i-1,e&&j==mk,0,1); 38 else 39 { 40 if(j==4) 41 ans+=dfs(i-1,e&&j==mk,1,0); 42 else 43 ans+=dfs(i-1,e&&j==mk,0,0); 44 } 45 } 46 } 47 //cout<<ans<<" "<<i<<endl; 48 return e?ans:dp[i][e][o][p]=ans; 49 } 50 LL cal(LL x) 51 { 52 int g=0; 53 while(x) 54 { 55 d[g++] = x%10; 56 x/=10; 57 } 58 return dfs(g-1,1,0,0); 59 } 60 int main() 61 { 62 int t; 63 cin>>t; 64 memset(dp,-1,sizeof(dp)); 65 while(t--) 66 { 67 cin>>n; 68 cout<<cal(n)<<endl; 69 } 70 return 0; 71 }
