Submission #951657

#	Time	Username	Problem	Language	Result	Execution time	Memory
951657		qwe1rt1yuiop1	Fish 2 (JOI22_fish2)	C++14	25 / 100	4058 ms	9836 KiB

fish2

#include <bits/stdc++.h>
#define int long long
// using ll = long long;
#define all(x) x.begin(), x.end()
#define sz(x) (int)x.size()
using namespace std;
using pii = pair<int, int>;

vector<int> ll, rr, v, p, ok;

void dfs(int x, int l, int r)
{
    ok[x] = 1;
    if (ll[x] != -1 && v[x] <= p[x - 1] - p[l - 1])
        dfs(ll[x], l, x - 1);
    if (rr[x] != -1 && v[x] <= p[r] - p[x])
        dfs(rr[x], x + 1, r);
}

void solve()
{
    int n;
    cin >> n;
    v.assign(n + 1, 0);
    for (int i = 1; i <= n; ++i)
        cin >> v[i];
    auto v0 = v;
    int n0 = n;

    int q;
    cin >> q;
    while (q--)
    {
        int t, a, b;
        cin >> t >> a >> b;
        if (t == 1)
        {
            v0[a] = b;
            continue;
        }
        v.assign(1, 0);
        for (int i = a; i <= b; ++i)
            v.emplace_back(v0[i]);
        n = sz(v) - 1;
        p = v;
        for (int i = 1; i <= n; ++i)
            p[i] += p[i - 1];
        v[0] = INT_MAX, v.emplace_back(INT_MAX);
        --v[0];

        vector<int> l(n + 2, -1), r(n + 2, -1);

        vector<int> stk;
        stk.emplace_back(0);
        for (int i = 1; i <= n; ++i)
        {
            while (v[stk.back()] < v[i])
                stk.pop_back();
            l[i] = stk.back();
            stk.emplace_back(i);
        }
        stk.clear();
        stk.emplace_back(n + 1);
        for (int i = n; i >= 1; --i)
        {
            while (v[stk.back()] <= v[i])
                stk.pop_back();
            r[i] = stk.back();
            stk.emplace_back(i);
        }

        ll.assign(n + 2, -1), rr = ll;

        for (int i = 1; i <= n; ++i)
        {
            if (v[l[i]] < v[r[i]])
            {
                assert(rr[l[i]] == -1);
                rr[l[i]] = i;
            }
            else
            {
                assert(ll[r[i]] == -1);
                ll[r[i]] = i;
            }
        }

        ok.assign(n + 1, 0);
        dfs(rr[0], 1, n);
        cout << accumulate(all(ok), 0) << '\n';
    }
}

/*
 */

signed main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);

    solve();

    return 0;
}

Compilation message (stderr)

fish2.cpp: In function 'void solve()':
fish2.cpp:28:9: warning: unused variable 'n0' [-Wunused-variable]
   28 |     int n0 = n;
      |         ^~

• Subtask 1: 5 / 5
• Subtask 2: 8 / 8
• Subtask 3: 12 / 12
• Subtask 4: 0 / 23
• Subtask 5: 0 / 35
• Subtask 6: 0 / 17