Luogu 3932（公式推导）（浮游大陆的68号岛）

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
#define fil(a,b) memset(a,b,sizeof(a))
typedef long long ll;
const int MAXN=2e5+4;
const ll MOD=19260817;
int n,q;
ll d[MAXN],a[MAXN],das[MAXN],da[MAXN];
inline ll read() {
ll x=0;char c=getchar();
while (c<'0'||c>'9') c=getchar();
while (c>='0'&&c<='9') x=x*10+c-'0',c=getchar();
return x;
}
inline ll f(int l,int r,int p) {
if (l>r) return 0;
return ((das[r]-das[l-1]-(da[r]-da[l-1])*d[p]%MOD)%MOD+MOD)%MOD;
}
inline ll g(int l,int r,int p) {
if (l>r) return 0;
return (((da[r]-da[l-1])*d[p]%MOD-das[r]+das[l-1])%MOD+MOD)%MOD;
}
int main() {
//	freopen("P3932.in","r",stdin);
fil(d,0),fil(das,0),fil(da,0);
n=read(),q=read();
for (register int i=2;i<=n;++i) d[i]=(d[i-1]+read())%MOD;
for (register int i=1;i<=n;++i) a[i]=read();
for (register int i=1;i<=n;++i) das[i]=(das[i-1]+a[i]*d[i]%MOD)%MOD,da[i]=(da[i-1]+a[i])%MOD;
for (register int i=0;i<q;++i) {
int p=read(),l=read(),r=read();
if (p<l) printf("%lld\n",f(l,r,p));
else if (p>r) printf("%lld\n",g(l,r,p));
else printf("%lld\n",(f(p+1,r,p)+g(l,p-1,p))%MOD);
}
return 0;
}