[HDU2089] 不要62 [数位dp]

[ $\frak{Link}$]

---

真好啊
比插头dp好看多了（

---

#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cstdlib>
#include<cmath>
#include<cstring>
#include<cctype>
using namespace std;
int n,m,F[10][2]={},bit[10]={};
int dfs(int pos,int pre,bool lead,bool limit)
{
    if(!pos)return 1;
    if(!limit&&F[pos][lead]>0)return F[pos][lead];
    int ret=0, up=limit?bit[pos]:9;
    for(register int i=0;i<=up;++i)
    {
        if(i==2&&pre==6)continue;
        if(i==4)continue;;
        ret+=dfs(pos-1,i,i==6,limit&&i==bit[pos]);
    }
    if(!limit)F[pos][lead]=ret;
    return ret;
}
int solve(int x)
{
    bit[0]=0;
    while(x)
    {
        bit[++bit[0]]=x%10;
        x/=10;
    }
    return dfs(bit[0],-1,true,true);
}
int main()
{
    memset(F,-1,sizeof(F));
    while(~scanf("%d%d",&n,&m))
    {
        if(!(n||m))return 0;
        printf("%d\n",solve(m)-solve(n-1));
    }
    return 0;
}