Submission #996282

#	Time	Username	Problem	Language	Result	Execution time	Memory
996282		yanb	The Kingdom of JOIOI (JOI17_joioi)	C++14	60 / 100	4091 ms	82228 KiB

joioi

#include <bits/stdc++.h>

using namespace std;

#define int long long

bool good(int n, int m, vector<vector<int>> &a, int x) {
    int mn = 1e11, mx = -1e11;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            mn = min(mn, a[i][j]);
            mx = max(mx, a[i][j]);
        }
    }

    vector<vector<int>> need(n, vector<int>(m));
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            if (a[i][j] <= mx - x) need[i][j] += 1;
            if (a[i][j] >= mn + x) need[i][j] += 2;
            if (need[i][j] == 3) return 0;
        }
    }

    /*for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            switch (need[i][j]) {
                case 0: cout << "  "; break;
                case 1: cout << "- "; break;
                case 2: cout << "+ "; break;
                case 3: cout << "± ";
            }
        }
        cout << "\n";
    }*/

    for (int i = 0; i < n; i++) {
        bool ones = 1;
        for (int j = 0; j < m; j++) {
            if (need[i][j] == 1) {
                if (!ones) return 0;
            }
            if (need[i][j] == 2) {
                if (ones) ones = 0;
            }
        }
    }

    vector<int> depth(n, -1);
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            if (need[i][j] == 2) break;
            if (need[i][j] == 1) depth[i] = j;
            if (need[i][j] == 0) depth[i] = max(depth[i], min((i > 0 ? depth[i - 1] : (int)(1e9)), j));
        }
        //cout << depth[i] << " ";
    }
    //cout << "\n";

    for (int i = 0; i < n - 1; i++) {
        if (depth[i] < depth[i + 1]) return 0;
    }
    return 1;
}

int solve(int n, int m, vector<vector<int>> &a) {
    /*for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            cout << a[i][j] << " ";
        }
        cout << "\n";
    }*/

    int l = -1, r = 1e11;
    while (r - l > 1) {
        int md = (l + r) / 2;
        if (good(n, m, a, md)) {
            //cout << "Good " << md << "\n";
            r = md;
        } else {
            //cout << "Bad " << md << "\n";
            l = md;
        }
    }
    //cout << l << "\n\n";

    return l;
}

vector<vector<int>> fliph(int n, int m, vector<vector<int>> &a) {
    vector<vector<int>> ans(n, vector<int>(m));
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            ans[i][j] = a[i][m - j - 1];
        }
    }
    return ans;
}

vector<vector<int>> flipv(int n, int m, vector<vector<int>> &a) {
    vector<vector<int>> ans(n, vector<int>(m));
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            ans[i][j] = a[n - 1 - i][j];
        }
    }
    return ans;
}

vector<vector<int>> flips(int n, int m, vector<vector<int>> &a) {
    vector<vector<int>> ans(n, vector<int>(m));
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            ans[i][j] = -a[i][j];
        }
    }
    return ans;
}

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int n, m;
    cin >> n >> m;
    vector<vector<int>> a(n, vector<int>(m));

    for (int i = 0; i < n; i++)
        for (int j = 0; j < m; j++)
            cin >> a[i][j];

    int ans = solve(n, m, a);
    a = fliph(n, m, a);
    ans = min(ans, solve(n, m, a));
    a = flipv(n, m, a);
    ans = min(ans, solve(n, m, a));
    a = fliph(n, m, a);
    ans = min(ans, solve(n, m, a));
    a = flips(n, m, a);
    ans = min(ans, solve(n, m, a));
    a = fliph(n, m, a);
    ans = min(ans, solve(n, m, a));
    a = flipv(n, m, a);
    ans = min(ans, solve(n, m, a));
    a = fliph(n, m, a);
    ans = min(ans, solve(n, m, a));

    cout << ans << "\n";
}   

• Subtask 1: 15 / 15
• Subtask 2: 45 / 45
• Subtask 3: 0 / 40