Submission #1109911

#	Time	Username	Problem	Language	Result	Execution time	Memory
1109911		ljtunas	The Kingdom of JOIOI (JOI17_joioi)	C++17	0 / 100	12 ms	4176 KiB

joioi

// author : anhtun_hi , nqg
#include <bits/stdc++.h>
#define ll long long
#define ii pair<ll, ll>
#define fi first
#define se second
#define all(x) x.begin(), x.end()
#define reset(h, v)    memset(h, v, sizeof h)
#define Forv(i, a)     for(auto& i : a)
#define For(i, a, b)   for(int i = a; i <= b; ++i)
#define Ford(i, a, b)  for(int i = a; i >= b; --i)
#define c_bit(i)     __builtin_popcountll(i)
#define Bit(mask, i)    ((mask >> i) & 1LL)
#define onbit(mask, i)  ((mask) bitor (1LL << i))
#define offbit(mask, i) ((mask) &~ (1LL << i))
using namespace std;
namespace std {
    template <typename T, int D>
    struct _vector : public vector <_vector <T, D - 1>> {
        static_assert(D >= 1, "Dimension must be positive!");
        template <typename... Args>
        _vector(int n = 0, Args... args) : vector <_vector <T, D - 1>> (n, _vector <T, D - 1> (args...)) {}
    };
    template <typename T> struct _vector <T, 1> : public vector <T> {
        _vector(int n = 0, const T& val = T()) : vector <T> (n, val) {}
    };
    template <class A, class B> bool minimize(A &a, B b){return a > b ? a = b, true : false;}
    template <class A, class B> bool maximize(A &a, B b){return a < b ? a = b, true : false;}
}
const int dx[] = {0, 0, +1, -1}, dy[] = {-1, +1, 0, 0}, LOG = 20, base = 311, inf = 1e9 + 5;
const int MAXN = 2e3 + 5;
const  ll  mod = 1e9 + 7;
const  ll   oo = 1e18;

//#define int long long

int n, m; vector<vector<int>> a;
bool vs[MAXN][MAXN];
bool check(int val){
    int mn = inf, mx = 0; bool ok = false;
    mn = inf, mx = 0;
    reset(vs, 0);
    For(hang, 0, n - 1){
        for(int i = 0, j = -1; i < m; ++i){
            while(j < m - 1 && max(a[hang][j + 1], mx) - min(a[hang][j + 1], mn) <= val) {
                    ++j;
                    maximize(mx, a[hang][j]);
                    minimize(mn, a[hang][j]);
                    vs[hang][j] = 1;
            }
        }
    }
    mn = inf, mx = 0;
    For(i, 0, n - 1) For(j, 0, m - 1) if(!vs[i][j]) minimize(mn, a[i][j]), maximize(mx, a[i][j]);
    ok |= (mx - mn <= val);

    mn = inf, mx = 0;
    reset(vs, 0);
    For(hang, 0, n - 1) reverse(all(a[hang]));
    For(hang, 0, n - 1){
        for(int i = 0, j = -1; i < m; ++i){
            while(j < m - 1 && max(a[hang][j + 1], mx) - min(a[hang][j + 1], mn) <= val) {
                    ++j;
                    maximize(mx, a[hang][j]);
                    minimize(mn, a[hang][j]);
                    vs[hang][j] = 1;
            }
        }
    }
    For(hang, 0, n - 1) reverse(all(a[hang]));
    mn = inf, mx = 0;
    For(i, 0, n - 1) For(j, 0, m - 1) if(!vs[i][j]) minimize(mn, a[i][j]), maximize(mx, a[i][j]);
    ok |= (mx - mn <= val);
//
    mn = inf, mx = 0;
    reset(vs, 0);
    For(cot, 0, m - 1){
        for(int i = 0, j = -1; i < n; ++i){
            while(j < n - 1 && max(a[j + 1][cot], mx) - min(a[j + 1][cot], mn) <= val) {
                    ++j;
                    maximize(mx, a[j][cot]);
                    minimize(mn, a[j][cot]);
                    vs[j][cot] = 1;
            }
        }
    }
    mn = inf, mx = 0;
    For(i, 0, n - 1) For(j, 0, m - 1) if(!vs[i][j]) minimize(mn, a[i][j]), maximize(mx, a[i][j]);
    ok |= (mx - mn <= val);
//
    mn = inf, mx = 0;
    reset(vs, 0);
    For(cot, 0, m - 1){
        for(int i = n - 1, j = n; i >= 0; --i){
            while(j > 0 && max(a[j - 1][cot], mx) - min(a[j - 1][cot], mn) <= val) {
                    --j;
                    maximize(mx, a[j][cot]);
                    minimize(mn, a[j][cot]);
                    vs[j][cot] = 1;
            }
        }
    }
    mn = inf, mx = 0;
    For(i, 0, n - 1) For(j, 0, m - 1) if(!vs[i][j]) minimize(mn, a[i][j]), maximize(mx, a[i][j]);
    ok |= (mx - mn <= val);

    return ok;
}

void Solve() {
    cin >> n >> m;
    a.assign(n, vector<int>(m, 0));
    For(i, 0, n - 1) For(j, 0, m - 1) cin >> a[i][j];
    int l = -1, r = inf;
    while(r - l > 1){
        int mid = l + r >> 1;
        if(check(mid)) r = mid;
        else l = mid;
    }
    cout << r << '\n';
//    cout <<
}

int32_t main() {
    cin.tie(0) -> sync_with_stdio(0);
    if(fopen("JOI17_joioi.inp", "r")) {
        freopen("JOI17_joioi.inp", "r", stdin);
        freopen("JOI17_joioi.out", "w", stdout);
    }

    int t = 1;
//    cin >> t;

    for (int test = 1; test <= t; test++) {
        Solve();
    }
    return 0;
}

Compilation message (stderr)

joioi.cpp: In function 'void Solve()':
joioi.cpp:116:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  116 |         int mid = l + r >> 1;
      |                   ~~^~~
joioi.cpp: In function 'int32_t main()':
joioi.cpp:127:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  127 |         freopen("JOI17_joioi.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
joioi.cpp:128:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  128 |         freopen("JOI17_joioi.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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