$rt$,测试点$3$与测试点$9$没过

#include<bits/stdc++.h>
using namespace std;
long long ans,a[100005],m,n,b[100005],i,j,l,r,mid;
long long check(long long x){
    l=0;r=m;
    while(l<=r){
        mid=(l+r)/2;
        if(b[mid]>=x)r=mid-1;
        else l=mid+1;
//        cout<<l<<"=L "<<r<<"=r "<<mid<<"\n";
    }
	
	if(l==0){
	   	return abs(b[l]-x);
	}
	else{
		int q=abs(x-b[l]),p=abs(b[r]-x);/*cout<<p<<" "<<q<<"\n";*/
    	return min(p,q);
	} 

//    cout<<a[l]<<" "<<x<<"\n";
	
    
}
int main(){
    scanf("%lld %lld",&m,&n);
    for(i=0;i<m;i++)scanf("%lld",&b[i]);
    sort(b,b+m);
    for(i=0;i<n;i++)scanf("%lld",&a[i]);
    sort(a,a+n);
    for(i=0;i<n;i++){
        ans+=check(a[i]);
//        printf("%lld\n",ans);
    }
    printf("%lld",ans);
    return 0;
}