测试

这是一个测试
做测试

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define endl "\n"
struct pos {
    int day, night;
};
bool cmp(pos a, pos b) {
    return a.night - a.day > b.night - b.day;
}
int main() {
    ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
    int n, k;
    cin >> n >> k;
    vector<pos>a(n + 1);
    for (int i = 1; i <= n; i++)cin >> a[i].day >> a[i].night;
    sort(a.begin() + 1, a.end(), cmp);
    ll ans = 0;
    int cnt = 0;
    for (int i = 1; i <= n; i++)
    {
        if (cnt <= k) {
            ans += a[i].night;
        }
        else {
            ans += a[i].day;
        }
        cnt++;
    }
    cout << ans;
    return 0;
}