Submission #998305

#	Time	Username	Problem	Language	Result	Execution time	Memory
998305		LOLOLO	Feast (NOI19_feast)	C++17	100 / 100	151 ms	20880 KiB

feast

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
 
#define           f     first
#define           s     second
#define           pb    push_back
#define           ep    emplace
#define           eb    emplace_back
#define           lb    lower_bound
#define           ub    upper_bound
#define       all(x)    x.begin(), x.end()
#define      rall(x)    x.rbegin(), x.rend()
#define   uniquev(v)    sort(all(v)), (v).resize(unique(all(v)) - (v).begin())
#define     mem(f,x)    memset(f , x , sizeof(f))
#define        sz(x)    (ll)(x).size()
#define  __lcm(a, b)    (1ll * ((a) / __gcd((a), (b))) * (b))
#define          mxx    *max_element
#define          mnn    *min_element
#define    cntbit(x)    __builtin_popcountll(x)
#define       len(x)    (int)(x.length())
 
const int N = 3e5 + 10;
int p[N], sz[N], l[N], r[N], a[N];
ll val[N];
 
set <pair <ll, ll>> st;
 
int get(int x) {
    return p[x] ? get(p[x]) : x;
}
 
void unite(int a, int b) {
    a = get(a), b = get(b);
    if (a == b)
        return;
 
    if (sz[a] < sz[b])
        swap(a, b);
 
    sz[a] += sz[b];
    val[a] += val[b];
    p[b] = a;
    l[a] = min(l[a], l[b]);
    r[a] = max(r[a], r[b]);
}
 
int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    //freopen("solution.inp", "r", stdin);
    //freopen("solution.ans", "w", stdout);
    int n, k;
    cin >> n >> k;
 
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
        sz[i] = 1;
        l[i] = r[i] = i;
    }
 
    while (a[n] <= 0 && n)
        n--;
 
    if (n == 0) {
        cout << 0 << '\n';
        return 0;
    } 
 
    int ft = 1;
    while (a[ft] <= 0)
        ft++;
 
    for (int j = ft; j <= n; j++) 
        a[j - ft + 1] = a[j];

    n -= (ft - 1);

    for (int i = 1; i <= n; i++) {
        val[i] = a[i];
    }
 
    for (int i = 1; i < n; i++) 
        if ((a[i] >= 0) == (a[i + 1] >= 0))
            unite(i, i + 1);
 
    for (int i = 1; i <= n; i++) 
        if (get(i) == i) 
            st.insert({abs(val[get(i)]), i});
 
    int ss = 1;
    while (sz(st) > k * 2) {
        auto it = *st.begin(); 
        st.erase(it);
        int p = it.s;
 
        if (l[p] > ss) {
            int x = get(l[p] - 1);
            st.erase({abs(val[x]), x});
            unite(p, x);
        }
 
        if (r[p] < n) {
            int x = get(r[p] + 1);
            st.erase({abs(val[x]), x});
            unite(p, x);
        }
 
        p = get(p);
        st.insert({abs(val[p]), p});
 
        while (val[get(n)] < 0) {
            st.erase({abs(val[get(n)]), get(n)});
            n = l[get(n)] - 1;
        }
 
        while (val[get(ss)] < 0) {
            st.erase({abs(val[get(ss)]), get(ss)});
            ss = r[get(ss)] + 1;
        }
    }
 
    ll ans = 0;
    for (auto x : st)
        ans += max((ll)0, val[x.s]);

    cout << ans << '\n';
    return 0;
}

• Subtask 1: 4 / 4
• Subtask 2: 8 / 8
• Subtask 3: 18 / 18
• Subtask 4: 10 / 10
• Subtask 5: 11 / 11
• Subtask 6: 20 / 20
• Subtask 7: 29 / 29