Submission #723460

#	Time	Username	Problem	Language	Result	Execution time	Memory
723460		lovrot	Nautilus (BOI19_nautilus)	C++17	66 / 100	1077 ms	1200 KiB

nautilus

#include <cstdio> 
#include <cstring>

#pragma GCC optimize("Ofast")

using namespace std;

const int N = 510; 
const int lx[4] = {1, -1, 0, 0}; 
const int ly[4] = {0, 0, -1, 1}; 

int n, m, q;
bool dp[2][N][N], mat[N][N]; 

int main() {
	scanf("%d%d%d", &n, &m, &q); 
	for(int i = 1; i <= n; i++) 
		for(int j = 1; j <= m; j++) {
			char c;
			scanf(" %c", &c); 
			dp[0][i][j] = c == '.'; 
			mat[i][j] = !dp[0][i][j]; 
		}
	bool flag = 1;
	for(int t = 0; t < q; t++) {
		char c;
		scanf(" %c", &c);
		// printf("%c\n", c);
		int x = -1; 
		if(c == 'S') x = 1;
		if(c == 'N') x = 0;
		if(c == 'W') x = 3;
		if(c == 'E') x = 2;

		if(x == -1) {
			memset(dp[flag], 0, sizeof(dp[flag]));
			for(int i = 1; i <= n; i++) 
				for(int j = 1; j <= m; j++)
					for(int k = 0; k < 4; k++)
						dp[flag][i][j] |= !mat[i][j] && dp[!flag][i + lx[k]][j + ly[k]];
		} else {
			for(int i = 1; i <= n; i++) 
				for(int j = 1; j <= m; j++)
					dp[flag][i][j] = !mat[i][j] && dp[!flag][i + lx[x]][j + ly[x]];
		}
		flag ^= 1;
	}
	int sol = 0;
	for(int i = 1; i <= n; i++)
		for(int j = 1; j <= m; j++)
			sol += dp[!flag][i][j]; 
	printf("%d\n", sol);
	return 0;
}

Compilation message (stderr)

nautilus.cpp: In function 'int main()':
nautilus.cpp:16:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |  scanf("%d%d%d", &n, &m, &q);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~~
nautilus.cpp:20:9: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   20 |    scanf(" %c", &c);
      |    ~~~~~^~~~~~~~~~~
nautilus.cpp:27:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   27 |   scanf(" %c", &c);
      |   ~~~~~^~~~~~~~~~~

• Subtask 1: 29 / 29
• Subtask 2: 37 / 37
• Subtask 3: 0 / 34