Submission #868619

#	Time	Username	Problem	Language	Result	Execution time	Memory
868619		mgl_diamond	Dango Maker (JOI18_dango_maker)	C++17	100 / 100	165 ms	53496 KiB

dango_maker

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ii = pair<int, int>;

#define foru(i, l, r) for(int i=(l); i<=(r); ++i)
#define ford(i, l, r) for(int i=(l); i>=(r); --i)
#define fore(x, v) for(auto &x : v)
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)x.size()

void setIO() {
  ios::sync_with_stdio(0);
  cin.tie(0); cout.tie(0);
  if (fopen("input.in", "r")) {
    freopen("input.in", "r", stdin);
    freopen("input.out", "w", stdout);
  }
}

const int N = 3003;
int n, m, proc[N][N];
char mat[N][N];
int ans = 0;
int dp[2][3];

bool can(int t, int i, int j) {
  if (t == 1) return mat[i][j-1] == 'R' && mat[i][j+1] == 'W';
  return mat[i-1][j] == 'R' && mat[i+1][j] == 'W';
}

int main() {
  setIO();

  cin >> n >> m;
  foru(i, 1, n) foru(j, 1, m) cin >> mat[i][j];

  foru(i, 1, n) foru(j, 1, m) if (mat[i][j] == 'G' && !proc[i][j]) {
    int u = i, v = j;
    int cur = 0, prv = 1;
    dp[prv][0] = dp[prv][1] = dp[prv][2] = 0;

    while (u <= n && v >= 1) {
      if (mat[u][v] != 'G') break;
      proc[u][v] = 1;
      memset(dp[cur], 0, sizeof(dp[cur]));

      dp[cur][0] = max({dp[prv][0], dp[prv][1], dp[prv][2]});
      if (can(1, u, v)) dp[cur][1] = max(dp[prv][0], dp[prv][1]) + 1;
      if (can(2, u, v)) dp[cur][2] = max(dp[prv][0], dp[prv][2]) + 1;

      cur ^= 1; prv ^= 1;
      ++u; --v;
    }

//    cout << i << " " << j << " " << max({dp[prv][0], dp[prv][1], dp[prv][2]});
    ans += max({dp[prv][0], dp[prv][1], dp[prv][2]});
  }

  cout << ans;
}

Compilation message (stderr)

dango_maker.cpp: In function 'void setIO()':
dango_maker.cpp:16:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |     freopen("input.in", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
dango_maker.cpp:17:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 |     freopen("input.out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 20 / 20
• Subtask 3: 67 / 67