【数位dp】不要62

#include<iostream>#include<cstdio>#include<cstring>using namespace std;int n,m,a[20],dp[20][2];int dfs(int pos,int pre,int sta,bool limit){    if(pos==-1) return 1;    if(!limit && dp[pos][sta]!=-1) return dp[pos][sta];    int up=limit?a[pos]:9,tmp=0;    for(int i=0;i<=up;i++){        if(i==4) continue;        if(pre==6&&i==2) continue;        tmp+=dfs(pos-1,i,i==6,limit&&i==a[pos]);    }    if(!limit) dp[pos][sta]=tmp;    return tmp;}int solve(int x){    int pos=0;    while(x){        a[pos++]=x%10;        x/=10;    }    return dfs(pos-1,-1,0,1);}int main(){    scanf("%d%d",&n,&m);    memset(dp,-1,sizeof(dp));    printf("%d",solve(m)-solve(n-1));}