求助

#include<cstdio>
#include<algorithm>
using namespace std;
const int mod=10007;
inline int read(){
	char ch=getchar();int x=0,f=1;
	while(ch<'0'||ch>'9'){if(ch=='-') f=-1;ch=getchar();}
	while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
	return x*f;
}
int n,m;
struct node{
	int num,color,id;
}a[100005];
bool cmp(node xr,node yr){
	if(xr.color!=yr.color) return xr.color<yr.color;
	return xr.id<yr.id;
}
int main(){
	n=read();m=read();
	for(int i=1;i<=n;i++) a[i].num=read();
	for(int i=1;i<=n;i++) a[i].color=read(),a[i].id=i;
	sort(a+1,a+n+1,cmp);int ans=0,i=1;
	while(i<=n){
		int j=i+1;
		while(a[j].color==a[i].color&&j<=n) j++;
		for(int k=i+1;k<j;k++){
			for(int now=k-1;now>=i;now--){
				if((a[k].id-a[now].id)%2) continue;
				ans+=(a[now].id+a[k].id)*(a[now].num+a[k].num)%mod;
			}
		}
		i=j;
	}
	printf("%d",ans);
	return 0;
}
/*先按颜色排，颜色相同按id排*/