[HDU 3555] Bomb

 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 typedef long long ll;
 4 ll dp[20][2];
 5 int dig[20];
 6 ll dfs(int dep,int four,int flag){
 7     if(!dep)return 1LL;
 8     if(!flag&&dp[dep][four]!=-1)return dp[dep][four];
 9     int lim=flag?dig[dep]:9;
10     ll ans=0;
11     for(int i=0;i<=lim;i++){
12         if(four&&i==9)continue;
13         ans+=dfs(dep-1,i==4?1:0,flag&(i==lim));
14     }
15     if(!flag)dp[dep][four]=ans;
16     return ans;
17 }
18 ll solve(ll x){
19     int dd=0;
20     while(x)dig[++dd]=x%10,x/=10;
21     return dfs(dd,0,1);
22 }
23 int main(){
24     memset(dp,-1,sizeof(dp));
25     int T;
26     scanf("%d",&T);
27     while(T--){
28         ll A;
29         scanf("%lld",&A);
30         printf("%lld\n",A-solve(A)+1);
31     }
32     return 0;
33 }