Codeforces 55D

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【题目分析】
数位DP

【代码】

#include <cstdio>#include <cstring>#include <iostream>#include <cmath>#include <algorithm>#define ll long longusing namespace std;int tt;int sa[2530],num[21];ll l,r;ll dp[21][2520][50];ll gcd(ll a,ll b){return b==0?a:gcd(b,a%b);}ll lcm(ll a,ll b){return a/gcd(a,b)*b;}inline void init(){    int cnt=0;    for (int i=1;i<=2520;++i) if (2520%i==0) sa[i]=++cnt;    memset(dp,-1,sizeof dp);}inline ll dfs(int pos,int psum,int plcm,bool flag){    if (pos==0) return psum%plcm==0;    if (!flag&&dp[pos][psum][sa[plcm]]!=-1)        return dp[pos][psum][sa[plcm]];    int end=flag?num[pos]:9;    ll ans=0;    for (int i=0;i<=end;++i)    {        int nsum=(psum*10+i)%2520;        int nlcm=plcm;        if (i) nlcm=lcm(plcm,i);        ans+=dfs(pos-1,nsum,nlcm,flag&&i==end);    }    if (!flag) return dp[pos][psum][sa[plcm]]=ans;    return ans;}inline ll cal(ll x){    memset(num,0,sizeof num);    int pos=0;    while (x)    {        num[++pos]=x%10;        x/=10;    }    return dfs(pos,0,1,1);}int main(){    init();    scanf("%d",&tt);    while (tt--)    {        scanf("%I64d%I64d",&l,&r);        printf("%I64d\n",cal(r)-cal(l-1));    }}

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