Submission #74598

#	Time	Username	Problem	Language	Result	Execution time	Memory
74598		garyye	Dango Maker (JOI18_dango_maker)	C++14	100 / 100	499 ms	10252 KiB

dango_maker

// author: gary
// created: 2018/09/04 09:19:17
#include <cassert>
#include <cctype>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <limits>
#include <utility>
#include <functional>
#include <string>
#include <bitset>
#include <deque>
#include <list>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <vector>
#include <algorithm>
#include <iostream>
#include <sstream>
using namespace std;
#define SZ(x) ( (int) (x).size() )
#define ALL(c) (c).begin(), (c).end()
#define CNT(c, x) ((c).find(x) != (c).end())
typedef pair<int, int> pii;
typedef long long ll;
template<class T> bool cmax(T& a, T b) { if(a < b) { a = b; return true; } return false; }
template<class T> bool cmin(T& a, T b) { if(a > b) { a = b; return true; } return false; }

const int N = 3005;

int n, m;
char G[N][N];

int get(int i, int j) {
  return i >= 0 && i < n && j >= 0 && j < m ? G[i][j] : 'X';
}

int down(int i, int j) {
  return get(i, j) == 'R' && get(i+1,j) == 'G' && get(i+2,j) == 'W';
}

int right(int i, int j) {
  return get(i, j) == 'R' && get(i,j+1) == 'G' && get(i,j+2) == 'W';
}

// 0 ... right , 1 ... down
int dp[2][2]; // ij-2, ij-1
int nx[2][2];

int main() {
  scanf("%d%d", &n, &m);
  for(int i = 0; i < n; i++) {
    scanf("%s", G[i]);
  }

  // for(int i = 0; i < n; i++) { printf("%d\n", right(i, 0)); }

  int ans = 0;
  for(int ij = 0; ij < n+m-1; ij++) {
    int mx = 0;
    deque<int> prev;
    memset(dp, 0, sizeof dp);
    for(int i = 0; i < n; i++) {
      int j = ij - i;
      if(j < 0 || j >= m || get(i, j) != 'R') {
        continue;
      }

      memset(nx, 0, sizeof nx);
      int touch2 = SZ(prev) == 2 && prev.front() + 2 == i;
      int touch1 = SZ(prev) >= 1 && prev.back() + 2 >= i;

      // Calc
      for(int d2 = 0; d2 < 2; d2++) {
        for(int d1 = 0; d1 < 2; d1++) {
          int ok = !(d1 && touch1) && !(d2 && touch2);
          cmax(nx[d1][0], dp[d2][d1] + ok * right(i, j));
          cmax(nx[d1][1], dp[d2][d1] + down(i, j));
        }
      }

      // Copy
      for(int d2 = 0; d2 < 2; d2++) {
        for(int d1 = 0; d1 < 2; d1++) {
          dp[d2][d1] = nx[d2][d1];
          cmax(mx, dp[d2][d1]);
        }
      }

      if(SZ(prev) == 2) {
        prev.pop_front();
      }
      prev.emplace_back(i);
    }
    // printf("ij=%d mx=%d\n", ij, mx);
    ans += mx;
  }
  printf("%d\n", ans);
  return 0;
}

Compilation message (stderr)

dango_maker.cpp: In function 'int main()':
dango_maker.cpp:57:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d", &n, &m);
   ~~~~~^~~~~~~~~~~~~~~~
dango_maker.cpp:59:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%s", G[i]);
     ~~~~~^~~~~~~~~~~~

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