Submission #632396

#	Time	Username	Problem	Language	Result	Execution time	Memory
632396		Ooops_sorry	Sandcastle 2 (JOI22_ho_t5)	C++14	100 / 100	1593 ms	16372 KiB

Main

#include<bits/stdc++.h>

using namespace std;

mt19937 rnd(51);

#define ll long long
#define pb push_back
#define ld long double

const int N = 50010;
int n, m, INF;
vector<vector<int>> a, any;
vector<pair<int,int>> d{{-1, 0}, {0, 1}, {1, 0}, {0, -1}};
vector<bool> used(4);
vector<vector<vector<int>>> side, two;
int mn[N], mx[N], cnt_up[N], sum_up[N], cnt_down[N], sum_down[N], cnt[N], sum[N];

bool check(int i, int j) {
    return i >= 0 && i < n && j >= 0 && j < m;
}

int get_max(int i, int j, vector<int> ban = {}) {
    int mx = -1;
    for (auto to : ban) {
        used[to] = 1;
    }
    for (int k = 0; k < 4; k++) {
        if (used[k]) {
            continue;
        }
        int x = i + d[k].first, y = j + d[k].second;
        if (check(x, y) && a[x][y] < a[i][j]) {
            mx = max(mx, a[x][y]);
        }
    }
    for (auto to : ban) {
        used[to] = 0;
    }
    return (mx == -1 ? 0 : a[i][j] - mx);
}

void build() {
    int h = max(n, m), w = min(n, m);
    a.resize(h);
    any.resize(h);
    side.resize(h);
    two.resize(h);
    for (int i = 0; i < h; i++) {
        a[i].resize(w);
        any[i].resize(w);
        side[i].resize(w);
        two[i].resize(w);
    }
    for (int i = 0; i < h; i++) {
        for (int j = 0; j < w; j++) {
            side[i][j].resize(4);
            two[i][j].resize(4);
        }
    }
}

// 0 -> U
// 1 -> R
// 2 -> D
// 3 -> L

signed main() {
#ifdef LOCAL
    freopen("input.txt", "r", stdin);
#endif // LOCAL
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cin >> n >> m;
    INF = n * m;
    build();
    if (n < m) {
        swap(n, m);
        for (int j = 0; j < m; j++) {
            for (int i = 0; i < n; i++) {
                cin >> a[i][j];
            }
        }
    } else {
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                cin >> a[i][j];
            }
        }
    }
    ll ans = 0;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            any[i][j] = get_max(i, j);
            for (int k = 0; k < 4; k++) {
                side[i][j][k] = get_max(i, j, {k});
                two[i][j][k] = get_max(i, j, {k, (k + 1) % 4});
            }
        }
    }
    for (int j1 = 0; j1 < m; j1++) {
        for (int i = 0; i < n; i++) {
            mn[i] = mx[i] = a[i][j1];

            cnt_up[i] = (two[i][j1][3] == 0);
            sum_up[i] = two[i][j1][3];

            cnt[i] = (side[i][j1][3] == 0);
            sum[i] = side[i][j1][3];

            cnt_down[i] = (two[i][j1][2] == 0);
            sum_down[i] = two[i][j1][2];
        }
        for (int j2 = j1 + 1; j2 < m; j2++) {
            for (int i = 0; i < n; i++) {
                cnt_up[i] += (two[i][j2][0] == 0);
                sum_up[i] += two[i][j2][0];

                cnt[i] += (side[i][j2][1] == 0);
                sum[i] += side[i][j2][1];

                cnt_down[i] += (two[i][j2][1] == 0);
                sum_down[i] += two[i][j2][1];
            }
            for (int i = 0; i < n; i++) {
                mn[i] = min(mn[i], a[i][j2]);
                mx[i] = max(mx[i], a[i][j2]);
                if (j1 < j2 - 1) {
                    cnt_up[i] += (side[i][j2 - 1][0] == 0);
                    sum_up[i] += side[i][j2 - 1][0];

                    cnt_down[i] += (side[i][j2 - 1][2] == 0);
                    sum_down[i] += side[i][j2 - 1][2];

                    cnt[i] += (any[i][j2 - 1] == 0);
                    sum[i] += any[i][j2 - 1];
                }
            }
            for (int i1 = 0; i1 < n; i1++) {
                int cur_mn = mn[i1], cur_mx = mx[i1];
                int cntt = cnt_up[i1], summ = sum_up[i1];
                for (int i2 = i1 + 1; i2 < n; i2++) {
                    cur_mn = min(cur_mn, mn[i2]);
                    cur_mx = max(cur_mx, mx[i2]);
                    if (i2 - 1 > i1) {
                        cntt += cnt[i2 - 1];
                        summ += sum[i2 - 1];
                    }
                    if (cntt + cnt_down[i2] == 1 && summ + sum_down[i2] == cur_mx - cur_mn) {
                        ans++;
                    }
                }
            }
            for (int i = 0; i < n; i++) {
                cnt_up[i] -= (two[i][j2][0] == 0);
                sum_up[i] -= two[i][j2][0];

                cnt[i] -= (side[i][j2][1] == 0);
                sum[i] -= side[i][j2][1];

                cnt_down[i] -= (two[i][j2][1] == 0);
                sum_down[i] -= two[i][j2][1];
            }
        }
    }
    for (int i = 0; i < n; i++) {
        int last = 2, cnt = 0;
        for (int j = 1; j < m; j++) {
            if ((last ^ (a[i][j - 1] < a[i][j])) == 1) {
                ans += 1ll * cnt * (cnt + 1) / 2;
                cnt = 1;
            } else {
                cnt++;
            }
            last = (a[i][j - 1] < a[i][j]);
        }
        ans += 1ll * cnt * (cnt + 1) / 2;
    }
    for (int j = 0; j < m; j++) {
        int last = 2, cnt = 0;
        for (int i = 1; i < n; i++) {
            if ((last ^ (a[i - 1][j] < a[i][j])) == 1) {
                ans += 1ll * cnt * (cnt + 1) / 2;
                cnt = 1;
            } else {
                cnt++;
            }
            last = (a[i - 1][j] < a[i][j]);
        }
        ans += 1ll * cnt * (cnt + 1) / 2;
    }
    ans += n * m;
    cout << ans << endl;
    return 0;
}

• Subtask 1: 9 / 9
• Subtask 2: 10 / 10
• Subtask 3: 5 / 5
• Subtask 4: 56 / 56
• Subtask 5: 20 / 20