Submission #395468

#	Time	Username	Problem	Language	Result	Execution time	Memory
395468		vishesh312	The Kingdom of JOIOI (JOI17_joioi)	C++17	100 / 100	1004 ms	70620 KiB

joioi

#include "bits/stdc++.h"
using namespace std;
/*
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
using ordered_set = tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update>;
*/

#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define sz(x) (int)(x).size()

using ll = long long;
const int mod = 1e9+7;

int n, m, mx = 0, mn = (1<<30);
vector<vector<int>> v;

bool chk(int x) {
    int last = -1;
    for (int i = 0; i < n; ++i) {
        int cur = -1;
        bool f = false;
        for (int j = 0; j < m; ++j) {
            if (v[i][j] < mx - x) {
                if (v[i][j] > mn + x or f) return false;
                cur = j;
            } else if (v[i][j] > mn + x) {
                if (j <= last) return false;
                f = true;
            }
        }
        last = max(last, cur);
    }
    return true;
}

int go() {
    int lo = 0, hi = mx - mn;
    while (lo < hi) {
        int mid = (lo + hi) / 2;
        if (chk(mid)) {
            hi = mid;
        } else {
            lo = mid + 1;
        }
    }
    return lo;
}

void solve(int tc) {
    cin >> n >> m;
    v.resize(n, vector<int>(m));
    for (auto &x : v) for (auto &y : x) {
        cin >> y;
        mx = max(mx, y);
        mn = min(mn, y);
    }
    auto a = v;
    int ans = mx - mn;
    ans = min(ans, go());
    for (int i = 0; i < n; ++i)
        for (int j = 0; j < m; ++j)
            v[i][j] = a[i][m-j-1];
    ans = min(ans, go());
    for (int i = 0; i < n; ++i)
        for (int j = 0; j < m; ++j)
            v[i][j] = a[n-i-1][j];
    ans = min(ans, go());
    for (int i = 0; i < n; ++i)
        for (int j = 0; j < m; ++j)
            v[i][j] = a[n-i-1][m-j-1];
    ans = min(ans, go());
    cout << ans << '\n';
}

signed main() {
    cin.tie(0)->sync_with_stdio(0);
    int tc = 1;
    //cin >> tc;
    for (int i = 1; i <= tc; ++i) solve(i);
    return 0;
}

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