EZOJ #81

#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
#include<algorithm>
#include<cctype>
#include<cmath>
#include<cstdlib>
#include<queue>
#include<ctime>
#include<vector>
#include<set>
#include<map>
#include<stack>
using namespace std;
int a[100100],b[100100];
inline int ra(){
    int x=0,f=1;char s=getchar();
    while(!isdigit(s)){if(s==‘-‘)f=-1;s=getchar();}
    while(isdigit(s))x=(x<<3)+(x<<1)+(s-‘0‘),s=getchar();
    return x*f;
}
int main(){
    int n,m,i,j,k,t;
    scanf("%d",&t);
    while(t--){
      long long Ans=0;
      scanf("%d%d",&n,&m);
      for(i=1;i<=n;i++)a[i]=ra();
      for(i=1;i<=m;i++)b[i]=ra();
      sort(a+1,a+n+1);
      sort(b+1,b+m+1);
      i=n;j=1;
      while(i>0&&j<=m){
          if(a[i]>b[j]){
            Ans+=(a[i]-b[j]);
          i--,j++;    
        }else break;
      }
      printf("%lld\n",Ans);
    }  
    return 0;
}