【贪心】Codeforces Round #402 (Div. 2) C. Dishonest Sellers

#include<cstdio>
#include<algorithm>
using namespace std;
struct Point
{
int x,y;
}a[200010];
int n,K,ans;
bool cmp(const Point &a,const Point &b)
{
return a.y-a.x>b.y-b.x;
}
int main()
{
//	freopen("c.in","r",stdin);
scanf("%d%d",&n,&K);
for(int i=1;i<=n;++i)
scanf("%d",&a[i].x);
for(int i=1;i<=n;++i)
scanf("%d",&a[i].y);
sort(a+1,a+n+1,cmp);
int i;
for(i=1;i<=n;++i)
{
if(i>K && a[i].y-a[i].x<0)
break;
ans+=a[i].x;
}
for(;i<=n;++i)
ans+=a[i].y;
printf("%d\n",ans);
return 0;
}