Submission #1196296

#	Time	Username	Problem	Language	Result	Execution time	Memory
1196296		LGQ_A3K25	Cultivation (JOI17_cultivation)	C++20	80 / 100	2095 ms	3016 KiB

cultivation

#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define db double
#define gcd(a,b) __gcd(a,b)
#define lcm(a,b) a*b / __gcd(a,b)
#define I first
#define II second
#define pb push_back
#define ii pair<int,int>
const int INF = 2e9;
const int N = 6e2 + 5;
const int MOD = 1e9 + 7;
int n, m, k;
namespace sub3
{
int tg[N], num[N];
ll ans = 1e18;
ii p[N];
array<int, 3> cur[N], f[N][N]; // L, R, M
struct DQ
{
    deque<ii> q;
    inline void add(ii x)
    {
        while (q.size() && q.back().I <= x.I) q.pop_back();
        q.pb(x);
    }
    inline void del(int& x)
    {
        while (q.size() && q.front().II <= x) q.pop_front();
    }
    inline int get()
    {
        if (q.empty()) return INF; else
            return q.front().I;
    }
} L, R, M;
    inline void init()
    {
        for (int l = 1; l <= k; l++)
        {
            int sz = 0;
            for (int r = l; r <= k; r++)
            {
                int mx = p[r].II;
                for (int i = 1; i <= sz; i++)
                    if (mx < tg[i]) swap(tg[i], mx);
                tg[++sz] = mx;
                f[l][r][0] = tg[1] - 1;
                f[l][r][1] = m - tg[sz];
                for (int i = 1; i < sz; i++)
                    f[l][r][2] = max(f[l][r][2], tg[i + 1] - tg[i] - 1);
//                cout << l << ' ' << r << ' ' << f[l][r][0] << ' ' << f[l][r][1] << ' ' << f[l][r][2] << '\n';
            }
        }
    }
    inline void solve(int le)
    {
        if (le >= ans) return;
        int sz = 0;
        for (int l = 1, r = 1; l <= k; l++)
        {
            while (r <= k && p[r].I <= p[l].I + le)
            {
                int val = p[r++].I;
                if (val > num[sz]) num[++sz] = val;
            }
            if (p[l].I + le + 1 > num[sz]) num[++sz] = p[l].I + le + 1;
        }
        for (int i = 1, l = 1, r = 1; i <= sz; i++)
        {
            while (l <= k && !(p[l].I <= num[i] && num[i] <= p[l].I + le)) l++;
            r = max(r, l);
            while (r <= k && p[r].I <= num[i] && num[i] <= p[r].I + le) r++;
            if (l > k) cur[i] = {INF, INF, INF}; else
                cur[i] = f[l][r - 1];
        }
        for (int l = 1, r = 1; l <= sz; l++)
        {
            r = max(r, l);
            while (r <= sz && num[r] < num[l] + n)
            {
                L.add({cur[r][0], r});
                R.add({cur[r][1], r});
                M.add({cur[r][2], r++});
            }
//            cout << le << ' ' << L.get() << ' ' << R.get() << ' ' << M.get() << '\n';
            ans = min(ans, 1ll * le + 1ll * max(L.get() + R.get(), M.get()));
            L.del(l);
            R.del(l);
            M.del(l);
        }
    }
    int main()
    {
        for (int i = 1; i <= k; i++) cin >> p[i].I >> p[i].II;
        vector<int> t;
        sort(p + 1, p + k + 1);
        for (int i = 1; i <= k; i++)
        {
            t.pb(p[i].I - 1);
            t.pb(n - p[i].I);
            for (int j = 1; j <= k; j++)
            {
                t.pb(max(0, p[j].I - p[i].I - 1));
                t.pb(p[i].I - 1 + n - p[j].I);
            }
        }
        sort(t.begin(), t.end());
        t.resize(unique(t.begin(), t.end()) - t.begin());
//        for (auto c : t) cout << c << ' ';cout << '\n';
        init();
        for (auto l : t) solve(l);
        cout << ans;
        return 0;
    }
}
int32_t main()
{
#define TASKNAME ""
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    if (fopen(TASKNAME".inp","r" ))
    {
        freopen(TASKNAME".inp","r",stdin);
        freopen(TASKNAME".ans","w",stdout);
    }
    cin >> n >> m >> k;
//    if (max(n, m) <= 40) sub1 :: main(); else
//        if (k <= 25) sub2 :: main(); else
            sub3 :: main();
    return 0;
}

Compilation message (stderr)

cultivation.cpp: In function 'int32_t main()':
cultivation.cpp:129:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  129 |         freopen(TASKNAME".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
cultivation.cpp:130:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  130 |         freopen(TASKNAME".ans","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 15 / 15
• Subtask 4: 30 / 30
• Subtask 5: 20 / 20
• Subtask 6: 0 / 20