Submission #922999

#	Time	Username	Problem	Language	Result	Execution time	Memory
922999		Ianis	Maxcomp (info1cup18_maxcomp)	C++17	100 / 100	93 ms	17228 KiB

maxcomp

#ifdef LOCAL
#include <iostream>
#include <fstream>
#include <iomanip>
#include <cassert>
#include <random>
#include <vector>
#include <queue>
#include <stack>
#include <set>
#include <map>
#else
#pragma GCC optimize("Ofast,unroll-loops")
#include <bits/stdc++.h>
#define cerr if (false) cerr 
#define endl '\n'
#endif

#define fi first
#define se second

#define sz(a) ((int)(a).size())
#define all(a) (a).begin(), (a).end()

#define lsb(x) (x & (-x))

#define bit(mask, i) (((mask) >> (i)) & 1)
#define popcount(x) __builtin_popcount(x)

#define YES cout << "YES" << endl
#define NO cout << "NO" << endl

using namespace std;

template <typename T>
bool ckmax(T &a, T b) { return a < b ? a = b, true : false; }
template <typename T>
bool ckmin(T &a, T b) { return a > b ? a = b, true : false; }

using ll = long long;
using pii = pair<int, int>;

const int NMAX = 1005;
const int INF  = 1e9+5;

int n, m;
int a[NMAX][NMAX];
int dp[NMAX][NMAX];

void read() {
   cin >> n >> m;
   for (int i = 1; i <= n; i++) {
      for (int j = 1; j <= m; j++)
         cin >> a[i][j];
   }
}

void reset() {
   for (int i = 0; i <= n + 1; i++)
      fill(dp[i], dp[i] + m + 2, INF);
}

int solve() {
   int ans = -1;

   reset();
   for (int i = 1; i <= n; i++) {
      for (int j = 1; j <= m; j++) {
         dp[i][j] = a[i][j] + 1;
         ckmin(dp[i][j], min(dp[i - 1][j], dp[i][j - 1]) + 1);
         ckmax(ans, a[i][j] - dp[i][j]);
      }
   }

   reset();
   for (int i = 1; i <= n; i++) {
      for (int j = m; j >= 1; j--) {
         dp[i][j] = a[i][j] + 1;
         ckmin(dp[i][j], min(dp[i - 1][j], dp[i][j + 1]) + 1);
         ckmax(ans, a[i][j] - dp[i][j]);
      }
   }

   reset();
   for (int i = n; i >= 1; i--) {
      for (int j = 1; j <= m; j++) {
         dp[i][j] = a[i][j] + 1;
         ckmin(dp[i][j], min(dp[i + 1][j], dp[i][j - 1]) + 1);
         ckmax(ans, a[i][j] - dp[i][j]);
      }
   }

   reset();
   for (int i = n; i >= 1; i--) {
      for (int j = m; j >= 1; j--) {
         dp[i][j] = a[i][j] + 1;
         ckmin(dp[i][j], min(dp[i + 1][j], dp[i][j + 1]) + 1);
         ckmax(ans, a[i][j] - dp[i][j]);
      }
   }

   return ans;
}

signed main() {
#ifdef LOCAL
   freopen("input.txt", "r", stdin);
#endif
   ios_base::sync_with_stdio(false);
   cin.tie(0);
   cout.tie(0);
   
   int t = 1;
//   cin >> t;

   while (t--) {
      read();
      cout << solve() << endl;
   }

   return 0;
}

• Subtask 1: 15 / 15
• Subtask 2: 15 / 15
• Subtask 3: 30 / 30
• Subtask 4: 40 / 40