Submission #735817

#	Time	Username	Problem	Language	Result	Execution time	Memory
735817		lovrot	Snake Escaping (JOI18_snake_escaping)	C++17	100 / 100	1910 ms	46300 KiB

snake_escaping

#include <cstdio> 
#include <vector> 
#include <cstring> 
#include <string> 
#include <algorithm>

#define X first
#define Y second
#define pb push_back

using namespace std; 

typedef pair<int, int> pii; 

const int LOG = 20; 
const int OFF = 1 << LOG; 

int n, m, P[OFF], sum;  

int POP[OFF], SUB[OFF], HIP[OFF];

int count(int mask) {
	return __builtin_popcount(mask); 
}

int main() {
	scanf("%d%d", &n, &m);
	int off = 1 << n;
	for(int i = 0; i < off; i++) {
		char c;
		scanf(" %c", &c);
		P[i] = c - '0'; 
		SUB[i] = HIP[i] = P[i];
		sum += P[i];
		POP[i] = count(i);
	}
	for(int i = 0; i < n; i++)
		for(int mask = 0; mask < off; mask++) {
			if(mask & 1 << i) SUB[mask] += SUB[mask ^ 1 << i]; 
			else HIP[mask] += HIP[mask ^ 1 << i]; 
		}
	for(int t = 0; t < m; t++) {
		int zer = 0; 
		int one = 0; 
		int que = 0;
		for(int i = 0, j = n - 1; i < n; i++, j--) {
			char c;
			scanf(" %c", &c);
			if(c == '?') que |= 1 << j;
			else if (c == '1') one |= 1 << j;
			else zer |= 1 << j;
		}
		int nim = min({POP[zer], POP[que], POP[one]}); 
		int sol = 0; 
		if(POP[zer] == nim) { //0
			for(int mask = zer; ; mask = (mask - 1) & zer) {
				sol += (POP[mask] & 1 ? -1 : 1) * HIP[mask | one]; 
				if(mask == 0) break;
			}
		} else if(POP[one] == nim) { //1
			for(int mask = one; ; mask = (mask - 1) & one) {
				sol += (POP[mask] & 1 ? -1 : 1) * SUB[que | (one ^ mask)]; 
				if(mask == 0) break;
			}
		} else { //?
			for(int mask = que; ; mask = (mask - 1) & que) {
				sol += P[mask | one];
				if(mask == 0) break;
			}
		}
		printf("%d\n", sol); 
	}
	return 0; 
}

Compilation message (stderr)

snake_escaping.cpp: In function 'int main()':
snake_escaping.cpp:27:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   27 |  scanf("%d%d", &n, &m);
      |  ~~~~~^~~~~~~~~~~~~~~~
snake_escaping.cpp:31:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 |   scanf(" %c", &c);
      |   ~~~~~^~~~~~~~~~~
snake_escaping.cpp:48:9: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   48 |    scanf(" %c", &c);
      |    ~~~~~^~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 7 / 7
• Subtask 3: 10 / 10
• Subtask 4: 53 / 53
• Subtask 5: 25 / 25