【bzoj4542】[Hnoi2016]大数

#include<algorithm>
#include<iostream>
#include<cstdlib>
#include<cstring>
#include<cstdio>
#include<cmath>
using namespace std;
 
typedef long long LL;
  
#define N 100010
 
struct Node
{
    LL val;
    int id;
}md[N];
 
struct data
{
    int l,r,id;
}ask[N];
 
char s[N];
 
LL c[N],d[N],h[N];
LL a[N];
 
LL p;
int m,n;
int l,r;
 
int len,K;
 
int cmp(Node aa,Node bb)
{
    return aa.val<bb.val;
}
 
int cmp2(data aa,data bb)
{
    return aa.l/K==bb.l/K ? aa.r<bb.r : aa.l<bb.l;
}
 
void work()
{
    for (int i=1;i<=len;i++)
    {
        d[i]=d[i-1]+((s[i-1]-'0')%p ? 0 : i);
        c[i]=c[i-1]+((s[i-1]-'0')%p==0);
    }
    scanf("%d",&m);
    while (m--)
    {
        scanf("%d%d",&l,&r);
        printf("%lld
",d[r]-d[l-1]-(c[r]-c[l-1])*(l-1));
    }
}
 
int main()
{
    scanf("%lld",&p);
    scanf("%s",s);
    len=strlen(s);
    K=sqrt(len)+1;
    if (p==2 || p==5)
    {
        work();
        return 0;
    }
    LL res=1;
    for (int i=len-1;i>=0;i--)
    {
        md[i].val=(md[i+1].val+(s[i]-'0')*res)%p;
        md[i].id=i;
        res=res*10%p;
    }
    md[len].id=len;
    sort(md,md+len+1,cmp);
    res=0;
    for (int i=0;i<=len;i++)
    {
        if (i && md[i].val!=md[i-1].val)
            res++;
        h[md[i].id]=res;
    }
    scanf("%d",&m);
    for (int i=0;i<=m;i++)
    {
        scanf("%d%d",&ask[i].l,&ask[i].r);
        ask[i].l--;
        ask[i].id=i;
    }
    sort(ask,ask+m,cmp2);
    int L(0),R(-1);
    res=0;
    for (int i=0;i<m;i++)
    {
        while (R<ask[i].r)
            res+=c[h[++R]]++;
        while (R>ask[i].r)
            res-=--c[h[R--]];
        while (L>ask[i].l)
            res+=c[h[--L]]++;
        while (L<ask[i].l)
            res-=--c[h[L++]];
        a[ask[i].id]=res;
    }
    for (int i=0;i<m;i++)
        printf("%lld
",a[i]);
    return 0;
}