oj.uz

Submission #594570

# Submission time Handle Problem Language Result Execution time Memory
594570 2022-07-12T17:01:52 Z piOOE Sandcastle 2 (JOI22_ho_t5) C++17
100 / 100
 1016 ms 4784 KB 
#include <bits/stdc++.h>

using namespace std;

using ll = long long;

//O(min(H, W) * H * W)
//I also came up with O((H * W)^2) solution, but didn't know how to optimize it to O(min(H, W) * H * W)
//so now this is Radewoosh's solution

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n, m;
    cin >> n >> m;

    bool swapped = false;
    if (n > m) {
        swapped = true;
        swap(n, m);
    }

    vector<vector<int>> a(n, vector<int>(m));
    vector<int> yy;
    for (int i = 0; i < (swapped ? m : n); ++i) {
        for (int j = 0; j < (swapped ? n : m); ++j) {
            if (!swapped) {
                cin >> a[i][j];
                yy.push_back(a[i][j]);
            } else {
                cin >> a[j][i];
                yy.push_back(a[j][i]);
            }
        }
    }

    sort(yy.begin(), yy.end());
    yy.resize(unique(yy.begin(), yy.end()) - yy.begin());

    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < m; ++j) {
            a[i][j] = lower_bound(yy.begin(), yy.end(), a[i][j]) - yy.begin() + 1;
        }
    }

    const int dx[4] = {-1, 0, 1, 0};
    const int dy[4] = {0, 1, 0, -1};

    int ans = 0;
    int diff[16][n][m];

    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < m; ++j) {
            for (int mask = 0; mask < 16; ++mask) {
                int lower = 0;
                bool big = false;
                for (int k = 0; k < 4; ++k) {
                    if (mask >> k & 1) {
                        int nx = i + dx[k];
                        int ny = j + dy[k];
                        if (nx >= 0 && nx < n && ny >= 0 && ny < m) {
                            if (a[nx][ny] < a[i][j]) {
                                lower = max(lower, a[nx][ny]);
                            } else {
                                big = true;
                            }
                        }
                    }
                }
                diff[mask][i][j] = a[i][j] - lower + (big ? 0 : n * m + 1 - a[i][j]);
            }
        }
    }

    //now handle rectangles with width or length = 1
    for (int k = 0; k < n; ++k) {
        for (int i = 0; i < m;) {
            int j = i + 1;
            while (j < m && a[k][j] < a[k][j - 1]) {
                j += 1;
            }
            int len = j - i;
            ans += len * ((ll) len - 1) / 2;
            i = j;
        }

        for (int i = m - 1; i > -1;) {
            int j = i - 1;
            while (j > -1 && a[k][j] < a[k][j + 1]) {
                j -= 1;
            }
            int len = i - j;
            ans += len * ((ll) len - 1) / 2;
            i = j;
        }
    }
    for (int k = 0; k < m; ++k) {
        for (int i = 0; i < n;) {
            int j = i + 1;
            while (j < n && a[j][k] < a[j - 1][k]) {
                j += 1;
            }
            int len = j - i;
            ans += len * ((ll) len - 1) / 2;
            i = j;
        }

        for (int i = n - 1; i > -1;) {
            int j = i - 1;
            while (j > -1 && a[j][k] < a[j + 1][k]) {
                j -= 1;
            }
            int len = i - j;
            ans += len * ((ll) len - 1) / 2;
            i = j;
        }
    }
    ans += n * m;

    int mid[n][m], L[n][m], R[n][m];

    for (int y = 0; y < m; ++y) {
        for (int x = 0; x < n; ++x) {
            mid[x][y] = (x ? mid[x - 1][y] : 0) + diff[15][x][y];
            L[x][y] = (x ? L[x - 1][y] : 0) + diff[7][x][y];
            R[x][y] = (x ? R[x - 1][y] : 0) + diff[13][x][y];
        }
    }

    //main part!
    for (int x1 = 0; x1 < n; ++x1) {
        for (int x2 = x1 + 1; x2 < n; ++x2) {
            vector<int> valMid(m), valR(m), valL(m);
            for (int y = 0; y < m; ++y) {
                valMid[y] = mid[x2 - 1][y] - mid[x1][y] + diff[14][x1][y] + diff[11][x2][y];
                valR[y] = R[x2 - 1][y] - R[x1][y] + diff[12][x1][y] + diff[9][x2][y];
                valL[y] = L[x2 - 1][y] - L[x1][y] + diff[6][x1][y] + diff[3][x2][y];
            }
            unordered_map<int, int> cnt;
            int prefix = 0;
            for (int y1 = 0; y1 < m; ++y1) {
                if (y1 > 0) {
                    prefix += valMid[y1 - 1];
                    ++cnt[prefix - valL[y1 - 1]];
                }
                ans += cnt[prefix + valR[y1] - (n * m + 1)];
            }
        }
    }
    cout << ans;
    return 0;
}

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 17 ms 4620 KB Output is correct
3 Correct 23 ms 4492 KB Output is correct
4 Correct 18 ms 4624 KB Output is correct
5 Correct 22 ms 4664 KB Output is correct
6 Correct 23 ms 4624 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct

Subtask #3
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 2 ms 340 KB Output is correct
9 Correct 5 ms 444 KB Output is correct
10 Correct 2 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 1 ms 340 KB Output is correct
13 Correct 5 ms 340 KB Output is correct
14 Correct 3 ms 340 KB Output is correct
15 Correct 4 ms 340 KB Output is correct
16 Correct 5 ms 340 KB Output is correct

Subtask #4
56.0 / 56.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 2 ms 340 KB Output is correct
9 Correct 5 ms 444 KB Output is correct
10 Correct 2 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 1 ms 340 KB Output is correct
13 Correct 5 ms 340 KB Output is correct
14 Correct 3 ms 340 KB Output is correct
15 Correct 4 ms 340 KB Output is correct
16 Correct 5 ms 340 KB Output is correct
17 Correct 3 ms 852 KB Output is correct
18 Correct 40 ms 908 KB Output is correct
19 Correct 11 ms 972 KB Output is correct
20 Correct 10 ms 920 KB Output is correct
21 Correct 22 ms 920 KB Output is correct
22 Correct 34 ms 920 KB Output is correct
23 Correct 32 ms 892 KB Output is correct
24 Correct 28 ms 860 KB Output is correct
25 Correct 39 ms 924 KB Output is correct
26 Correct 42 ms 972 KB Output is correct
27 Correct 45 ms 852 KB Output is correct
28 Correct 46 ms 916 KB Output is correct

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 2 ms 340 KB Output is correct
9 Correct 5 ms 444 KB Output is correct
10 Correct 2 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 1 ms 340 KB Output is correct
13 Correct 5 ms 340 KB Output is correct
14 Correct 3 ms 340 KB Output is correct
15 Correct 4 ms 340 KB Output is correct
16 Correct 5 ms 340 KB Output is correct
17 Correct 3 ms 852 KB Output is correct
18 Correct 40 ms 908 KB Output is correct
19 Correct 11 ms 972 KB Output is correct
20 Correct 10 ms 920 KB Output is correct
21 Correct 22 ms 920 KB Output is correct
22 Correct 34 ms 920 KB Output is correct
23 Correct 32 ms 892 KB Output is correct
24 Correct 28 ms 860 KB Output is correct
25 Correct 39 ms 924 KB Output is correct
26 Correct 42 ms 972 KB Output is correct
27 Correct 45 ms 852 KB Output is correct
28 Correct 46 ms 916 KB Output is correct
29 Correct 18 ms 4624 KB Output is correct
30 Correct 244 ms 4572 KB Output is correct
31 Correct 987 ms 4492 KB Output is correct
32 Correct 19 ms 4784 KB Output is correct
33 Correct 153 ms 4468 KB Output is correct
34 Correct 438 ms 4476 KB Output is correct
35 Correct 349 ms 3116 KB Output is correct
36 Correct 551 ms 4440 KB Output is correct
37 Correct 1006 ms 4444 KB Output is correct
38 Correct 987 ms 4432 KB Output is correct
39 Correct 984 ms 4468 KB Output is correct
40 Correct 986 ms 4420 KB Output is correct
41 Correct 962 ms 4432 KB Output is correct
42 Correct 1008 ms 4452 KB Output is correct
43 Correct 980 ms 4432 KB Output is correct
44 Correct 1016 ms 4464 KB Output is correct