在本机运行#1是对的但是在洛谷WA

本机运行结果:

#1数据

代码如下：

#include<bits/stdc++.h>
using namespace std;

vector<long long>school;

int main() {
//	freopen("P1678_1.in","r",stdin);
	int m,n;
	long long tot = 0;
	scanf("%d %d",&m,&n);
	for(int i = 0; i < m; ++ i) {
		long long x;
		scanf("%lld",&x);
		school.push_back(x);
	}
	sort(school.begin(),school.end());
	for(int i = 0; i < n; ++ i) {
		long long x;
		scanf("%lld",&x);
		auto r = lower_bound(school.begin(),school.end(),x);
		if(r == school.end()) {
			advance(r,-1);
			tot += abs(*r - x);
		} else {
			auto l = r;
			advance(l,-1);
			tot += min(abs(*l - x),abs(*r - x));
		}
	}
	printf("%lld",tot);
}