CF779C：Dishonest Sellers（贪心）

C. Dishonest Sellers

time limit per test
2 seconds

memory limit per test
256 megabytes

input
standard input

output
standard output

Igor found out discounts in a shop and decided to buy n items. Discounts at the store will last for a week and Igor knows about each
item that its price now is ai,
and after a week of discounts its price will be bi.

Not all of sellers are honest, so now some products could be more expensive than after a week of discounts.

Igor decided that buy at least k of items now, but wait with the rest
of the week in order to save money as much as possible. Your task is to determine the minimum money that Igor can spend to buy all n items.

Input

In the first line there are two positive integer numbers n and k (1 ≤ n ≤ 2·105, 0 ≤ k ≤ n)
— total number of items to buy and minimal number of items Igor wants to by right now.

The second line contains sequence of integers a1, a2, ..., an (1 ≤ ai ≤ 104)
— prices of items during discounts (i.e. right now).

The third line contains sequence of integers b1, b2, ..., bn (1 ≤ bi ≤ 104)
— prices of items after discounts (i.e. after a week).

Output

Print the minimal amount of money Igor will spend to buy all n items. Remember, he should buy at least k items
right now.

Examples

input

3 1
5 4 6
3 1 5

output

10

input

5 3
3 4 7 10 3
4 5 5 12 5

output

25

Note

In the first example Igor should buy item 3 paying 6. But items 1 and 2 he should buy after a week. He will pay 3 and 1 for them. So in total he will pay 6 + 3 + 1 = 10.

In the second example Igor should buy right now items 1, 2, 4 and 5, paying for them 3, 4, 10 and 3, respectively. Item 3 he should buy after a week of discounts, he will pay 5 for it. In total he will spend 3 + 4 + 10 + 3 + 5 = 25.

题意：n件物品，分别给出现在和以后的价格，现在必须购买k件或以上商品，其余可以以后再买，求买完所有商品支付的最小费用。

思路：按价格差排序就行。

# include <iostream>
# include <cstdio>
# include <cstring>
# include <algorithm>
using namespace std;
const int MAXN = 2e5;
struct node
{
int x, y;
}a[MAXN+1];

bool cmp(node a, node b)
{
return a.x-a.y < b.x-b.y;
}

int main()
{
int n, k, t;
while(~scanf("%d%d",&n,&k))
{
memset(a, 0, sizeof(a));
long long ans = 0;
for(int i=0; i<n; ++i)
scanf("%d",&a[i].x);
for(int i=0; i<n; ++i)
scanf("%d",&a[i].y);
sort(a, a+n, cmp);
for(int i=0; i<k; ++i)
ans += a[i].x;
t = n;
for(int i=k; k<n; ++i)
if(a[i].x < a[i].y)
ans += a[i].x;
else
{
t = i;
break;
}
for(int i=t; i<n; ++i)
ans += a[i].y;
printf("%I64d\n",ans);
}
return 0;
}