2020-07-24 烦恼的高考志愿

https://www.luogu.com.cn/problem/P1678

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cmath>
#include<cstring>
#include <map>
typedef long long LL;
using namespace std;

int read(){
    int x = 0,f = 1;
    char c = getchar();
    while (c<'0'||c>'9') {
        if (c=='-') {
            f = -1;
        }
        c = getchar();
    }
    while (c>='0'&&c<='9') {
        x = x*10+c-'0';
        c = getchar();
    }
    return x*f;
}

using namespace std;
int m,n,a[100002],score,pos,i;
long long ans;
int main()
{
    m = read();
    n = read();
    for(i=1;i<=m;i++){
        a[i] = read();
    }
    sort(a+1,a+m+1);//先排序一下
    
    for(i=1;i<=n;i++)
    {
        score = read();
        pos = lower_bound(a+1,a+m+1,score)-a;//返回查询到的位置
        if(pos == m+1){
            ans+=score-a[m];//特判比所有数都大的情况
        } else {
            if(pos==1){//特判比所有数都小的情况
                ans+=a[1]-score;
            }else{
                ans += min(abs(a[pos]-score),abs(score-a[pos-1]));
            }
        }
    }
    cout<<ans;
    return 0;
}
/*
4 3
513 598 567 689
500 600 550
============
32
*/