Submission #941481

#	Time	Username	Problem	Language	Result	Execution time	Memory
941481		Programmer123	Rectangles (IOI19_rect)	C++17	50 / 100	5027 ms	86284 KiB

rect

#ifndef LOCAL
#pragma GCC optimize("Ofast")
#pragma GCC target("avx2,sse4.2")
#endif

#include "rect.h"

long long count_rectangles(std::vector<std::vector<int> > a) {
    int N = a.size();
    int M = a[0].size();
    int maxv = 0;
    for (int i = 0; i < N; ++i) {
        for (int j = 0; j < M; ++j) {
            maxv = std::max(maxv, a[i][j]);
        }
    }
    if (maxv == 0) return 0;
    long long ans = 0;
    if (maxv == 1) {
        int pfx[N][M];
        pfx[0][0] = a[0][0];
        for (int i = 1; i < M; ++i) {
            pfx[0][i] = a[0][i] + pfx[0][i - 1];
        }
        for (int i = 1; i < N; ++i) {
            pfx[i][0] = a[i][0] + pfx[i - 1][0];
            for (int j = 1; j < M; ++j) {
                pfx[i][j] = a[i][j] + pfx[i - 1][j] + pfx[i][j - 1] - pfx[i - 1][j - 1];
            }
        }
        for (int i = 1; i < N - 1; ++i) {
            for (int j = 1; j < M - 1; ++j) {
                if (a[i][j] == 0 && a[i - 1][j] == 1 && a[i][j - 1] == 1) {
                    int below = -1, right = -1;
                    for (int k = i; k < N; ++k) {
                        if (a[k][j] == 1) {
                            below = k;
                            break;
                        }
                    }
                    for (int k = j; k < M; ++k) {
                        if (a[i][k] == 1) {
                            right = k;
                            break;
                        }
                    }
                    if (below == -1 || right == -1) continue;
                    int summid = pfx[below - 1][right - 1] - pfx[below - 1][j - 1] - pfx[i - 1][right - 1] +
                                 pfx[i - 1][j - 1];
                    if (summid) continue;
                    for (int k = i; k < below; ++k) {
                        if (!(a[k][j - 1] && a[k][right])) goto stop;
                    }
                    for (int k = j; k < right; ++k) {
                        if (!(a[i - 1][k] && a[below][k])) goto stop;
                    }
                    ans++;
                    stop:;
                }
            }
        }
        return ans;
    }
    if (N == 3) {
        bool works[M];
        works[0] = false;
        works[M - 1] = false;
        for (int i = 1; i < M - 1; ++i) {
            works[i] = a[1][i] < a[0][i] && a[1][i] < a[2][i];
        }
        for (int l = 1; l < M - 1; ++l) {
            if (!works[l]) continue;
            int max = a[1][l];
            for (int r = l; r < M - 1; ++r) {
                if (!works[r]) break;
                max = std::max(max, a[1][r]);
                if (max >= a[1][l - 1]) break;
                if (max >= a[1][r + 1]) continue;
                ans++;
            }
        }
        return ans;
    }
    int max[N];
    for (int u = 1; u < N - 1; ++u) {
        int maxc[M];
        for (int i = 0; i < M; ++i) {
            maxc[i] = a[u][i];
        }
        std::vector<int> alive;
        for (int i = 1; i < M - 1; ++i) {
            alive.push_back(i);
        }
        for (int d = u; d < N - 1; ++d) {
            for (auto i: alive) {
                maxc[i] = std::max(maxc[i], a[d][i]);
            }
            bool works[M];
            std::vector<int> working, nextalive;
            for (int i = 0; i < M; ++i) {
                works[i] = maxc[i] < a[u - 1][i] && maxc[i] < a[d + 1][i];
                if (works[i]) working.push_back(i);
                if (maxc[i] < a[u - 1][i]) nextalive.push_back(i);
            }
            alive = nextalive;
            for (auto l: working) {
                for (int i = u; i <= d; ++i) {
                    max[i] = a[i][l];
                }
                for (int r = l; r < M - 1; ++r) {
                    if (!works[r]) break;
                    for (int i = u; i <= d; ++i) {
                        max[i] = std::max(max[i], a[i][r]);
                    }
                    for (int i = u; i <= d; ++i) {
                        if (max[i] >= a[i][l - 1]) goto dead;
                    }
                    for (int i = u; i <= d; ++i) {
                        if (max[i] >= a[i][r + 1]) goto next;
                    }
                    ans++;
                    next:;
                }
                dead:;
            }
        }
    }
    return ans;
}

• Subtask 1: 8 / 8
• Subtask 2: 7 / 7
• Subtask 3: 12 / 12
• Subtask 4: 0 / 22
• Subtask 5: 10 / 10
• Subtask 6: 13 / 13
• Subtask 7: 0 / 28