Submission #51330

#	Time	Username	Problem	Language	Result	Execution time	Memory
51330		KieranHorgan	Orchard (NOI14_orchard)	C++17	25 / 25	348 ms	55324 KiB

orchard

#pragma GCC optimize("O3")
#include <bits/stdc++.h>

using namespace std;
#define endl '\n'
#define ll long long
#define int long long
#define ld long double
#define pii pair<int,int>
#define rand() abs((rand()<<15)|rand())
#define randll() abs(((long long)rand()<<30)|rand())

signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long seed;
  asm("rdtsc" : "=A"(seed));
  srand(seed);

  int n, m;
  cin >> n >> m;

  vector<vector<int>> grid(n+1, vector<int>(m+1, 0));
  vector<vector<int>> zs(n+1, vector<int>(m+1, 0));
  vector<vector<int>> os(n+1, vector<int>(m+1, 0));
  int totalOnes = 0;
  for(int i = 1; i <= n; i++) {
    for(int j = 1; j <= m; j++) {
      cin >> grid[i][j];
      if(grid[i][j])
        totalOnes++;
      os[i][j] = grid[i][j] + os[i-1][j] + os[i][j-1] - os[i-1][j-1];
      zs[i][j] =!grid[i][j] + zs[i-1][j] + zs[i][j-1] - zs[i-1][j-1];
    }
  }

  int ans = 1ll<<29;
  for(int top = 0; top < n; top++) {
    for(int bot = top+1; bot <= n; bot++) {
      int carried = totalOnes;
      for(int j = 1; j <= m; j++) {
        carried -= os[bot][j] - os[bot][j-1] - os[top][j] + os[top][j-1];
        carried += zs[bot][j] - zs[bot][j-1] - zs[top][j] + zs[top][j-1];
        int single = (zs[bot][j] - zs[bot][j-1] - zs[top][j] + zs[top][j-1]) + (totalOnes - (os[bot][j] - os[bot][j-1] - os[top][j] + os[top][j-1]));
        carried = min(carried, single);
        ans = min(ans, carried);
      }
    }
  }
  cout << ans << endl;
}

• Subtask 1: 4 / 4
• Subtask 2: 4 / 4
• Subtask 3: 5 / 5
• Subtask 4: 3 / 3
• Subtask 5: 4 / 4
• Subtask 6: 5 / 5