CF 55D - Beautiful numbers（数位DP）

#include<cstdio>
#include<cstring>
#define mod 2520
ll dp[35][2520][100];
int bit[64],m[200],mnum;
int gcd(int a,int b){
    int tmp;
    while(a%b){
        tmp=b;
        b=a%b;
        a=tmp;
    }
    return b;
}
int lcm(int a,int b){
    return a*b/gcd(a,b);
}
//查最小公倍数的标号
int tfind(int x){
    int ll=1,rr=mnum;
    while(ll<=rr){
        int mid=(ll+rr)>>1;
        if(m[mid]<x)ll=mid+1;
        else rr=mid-1;
    }
    return ll;
}
void init(){
    memset(dp,-1,sizeof(dp));
    mnum=0;
    for(int i=1;i<=mod;++i)
        if(mod%i==0)
        m[++mnum]=i;
}
ll dfs(int i,int d,int c,int e){
    if(i==0)return d%m[c]?0:1;
    if(!e&&dp[i][d][c]!=-1)return dp[i][d][c];
    int l=e?bit[i]:9;
    ll num=0;
    for(int j=0;j<=l;++j)
    {
        int td=(d*10+j)%mod;
        int tc=c;
        if(j)tc=tfind(lcm(m[c],j));
        num+=dfs(i-1,td,tc,e&&(j==l));
    }
    return e?num:dp[i][d][c]=num;
}
ll solve(ll x){
    int len=0;
    while(x){
        bit[++len]=x%10;
        x/=10;
    }
    return dfs(len,0,1,1);
}
int main()
{
    int t;
    scanf("%d",&t);
    init();
    ll x,y;
    while(t--){
        scanf("%I64d%I64d",&x,&y);
        printf("%I64d\n",solve(y)-solve(x-1));
    }
return 0;
}