Submission #1262517

#	Time	Username	Problem	Language	Result	Execution time	Memory
1262517		goulthen	The Kingdom of JOIOI (JOI17_joioi)	C++20	0 / 100	1 ms	320 KiB

joioi

//#pragma GCC optimize("O3")
//#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template <class T>
using Tree =
    tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
 
#define int long long
#define ll long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define fi first
#define se second
#define rep(i, a, b) for (int i = a; i <= b; ++i)
#define per(i, b, a) for (int i = b; i >= a; --i)
#define pb push_back
#define eb emplace_back
#define all(v) (v).begin(), (v).end()
#define lsb(x) (x)&(-x)
#define bug(x) cerr << #x << " " << x << endl;
 
void setIO(string name = "") {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr); cout.tie(nullptr);
    if (!name.empty()) {
        freopen((name + ".in").c_str(), "r", stdin);
        freopen((name + ".out").c_str(), "w", stdout);
    }
}
 
ll fexp(ll a, ll b, ll m) {
    if (b == 0) return 1LL;
    ll p = a;
    ll ans = 1;
    while (b > 0) {
        if (b % 2 != 0) ans = (ans * p) % m;
        p = (p * p) % m;
        b >>= 1;
    }
    return ans;
}
 
const int MAXN = 2e3 + 10;
const int INF = 1e18 + 5;
const int MOD = 1e9 + 7;
int a[MAXN][MAXN], mk[MAXN][MAXN],n,m;

int dx[] = {1,0,-1,0};
int dy[] = {0,1,0,-1};
void dfs(int i, int j, int K,int to=1,int mn=-INF) {
    if (mk[i][j]==to) return;
    mk[i][j] = to;
    rep(k,0,3) {
        int nx = i + dx[k], ny = j + dy[k];
        if (nx < 1 || nx > n || ny < 1 || ny > m || a[nx][ny] > K || a[nx][ny] < mn) continue;
        dfs(nx,ny,K,to,mn);
    }
}

void solve() {
    cin >> n >> m;
    rep(i,1,n) rep(j,1,m) cin >> a[i][j];
    int mi = 1, mj = 1;
    rep(i,1,n) rep(j,1,m) if (a[i][j] < a[mi][mj]) mi = i, mj = j;

    int lo = 0, hi = 1e9, ans=-1;
    while (lo <= hi) {
        int mid = (lo + hi) / 2;

        rep(i,1,n) rep(j,1,m) mk[i][j] = 0;
        dfs(mi,mj,a[mi][mj]+mid);

        int x = 0,y = 0, mn = INF, mx =-INF;

        bool ok = 1;
        rep(i,1,n) rep(j,1,m) if (!mk[i][j]) x = i, y = j, mn = min(mn,a[i][j]), mx = max(mx,a[i][j]);
        if(x > 0) dfs(x,y,mx, 2, mx-mid+1);

        rep(i,1,n) rep(j,1,m) ok &= (mk[i][j]!=0);

        if (mx-mn<=mid && ok) {
            hi = mid-1;
            ans = mid;
        } else {
            lo = mid + 1;
        }
    }
    cout << ans << '\n';
}

int32_t main() {
    setIO();
    int tt = 1;
    //cin >> tt;
 
    while (tt-- > 0) solve();
    return 0;
}

Compilation message (stderr)

joioi.cpp: In function 'void setIO(std::string)':
joioi.cpp:29:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   29 |         freopen((name + ".in").c_str(), "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
joioi.cpp:30:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 |         freopen((name + ".out").c_str(), "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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