南外集训 Day 17

The seventh day of intensive training at Nanjing Foreign Language School.
第一题和第二题，模拟
第三题

#include <bits/stdc++.h>
using namespace std;
int n, a[101010], l[100010], r[101000];
int main() {
    cin >> n;
    cin >> a[1];
    l[1] = a[1];
    for (int i = 2; i <= n; i++) {
        cin >> a[i];
        l[i] = __gcd(l[i - 1], a[i]);
    }
    r[n] = a[n];
    for (int i = n - 1; i >= 1; i--) {
        r[i] = __gcd(r[i + 1], a[i]);
    }
    int ans = 0;
    for (int i = 1; i <= n; i++) {
        if (i == 1) {
            ans = max(ans, r[2]);
            continue;
        }
        if (i == n) {
            ans = max(ans, l[n - 1]);
            continue;
        }
        ans = max(ans, __gcd(l[i - 1], r[i + 1]));
    }
    cout << ans;
    return 0;
}
``````cpp
#include 
using namespace std;
int n, ans, m;
struct Ree {
    int a, b;
} c[101010];
bool cmp(Ree a, Ree b) {
    if (a.a == b.a)
        return a.b > b.b;
    return a.a < b.a;
}
priority_queue q;
int main() {
    cin >> n >> m;
    for (int i = 1; i > c[i].a >> c[i].b;
    }
    sort(c + 1, c + 1 + n, cmp);
    int t = 1, ans = 0;
    for (int i = 1; i <= m; i++) {
        while (t <= n && c[t].a <= i) {
            q.push(c[t].b);
            t++;
        }
        if (q.size()) {
            ans += q.top();
            q.pop();
        }
    }
    cout << ans;
    return 0;
}