POJ 3208-Apocalypse Someday(数位dp)

#include <map>
#include <set>
#include <list>
#include <cmath>
#include <queue>
#include <stack>
#include <cstdio>
#include <vector>
#include <string>
#include <cctype>
#include <complex>
#include <cassert>
#include <utility>
#include <cstring>
#include <cstdlib>
#include <iostream>
#include <algorithm>
using namespace std;
typedef pair<int,int> PII;
typedef long long ll;
#define lson l,m,rt<<1
#define pi acos(-1.0)
#define rson m+1,r,rt<<11
#define All 1,N,1
#define read freopen("in.txt", "r", stdin)
const ll  INFll =0xfffffffffLL;
const int INF= 0x7ffffff;
const int mod =1000000007;
ll dp[64][2][2][2],n;
int bit[64];
ll dfs(int i,int j,int k,int l,int e){
    if(i==0)
    return l;
    if(!e&&dp[i][j][k][l]!=-1)
        return dp[i][j][k][l];
    int u=e?bit[i]:9;
    ll num=0;
    for(int v=0;v<=u;++v){
        if(l==1)
        num+=dfs(i-1,v==6,j,1,(e&&v==u));
        else
        num+=dfs(i-1,v==6,j,j&&k&&v==6,(e&&v==u));
    }
    return e?num:dp[i][j][k][l]=num;
}
ll getnum(ll x){
    int len=0;
    while(x){
        bit[++len]=x%10;
        x/=10;
    }
    return dfs(len,0,0,0,1);
}
int main()
{
    memset(dp,-1,sizeof(dp));
    int t;
    scanf("%d",&t);
    ll n;
    while(t--){
        scanf("%I64d",&n);
       ll l=1,r=INFll,mid;
        while(l<=r){
            mid=(l+r)>>1;
            if(getnum(mid)<n)l=mid+1;
            else r=mid-1;
        }
        printf("%I64d\n",l);
    }
return 0;
}