Submission #42389

#	Time	Username	Problem	Language	Result	Execution time	Memory
42389		RezwanArefin01	Snake Escaping (JOI18_snake_escaping)	C++14	65 / 100	2040 ms	65536 KiB

snake_escaping

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int, int> ii; 

ll dp[1 << 20], dp2[1 << 20], ans; 
string b, s; int l, q;

void recurr1(int i, int num, int tot) {
	if(i == l) {
		if(tot & 1) ans -= dp[num];
		else ans += dp[num];
		return; 
	}
	if(s[i] == '0') recurr1(i + 1, num << 1, tot); 
	else if(s[i] == '?') recurr1(i + 1, num << 1 | 1, tot);
	else {
		recurr1(i + 1, num << 1 | 1, tot); 
		recurr1(i + 1, num << 1, tot + 1);
	}
}

void recurr0(int i, int num, int tot) {
	if(i == l) {
		if(tot & 1) ans -= dp2[num];
		else ans += dp2[num];
		return; 
	}
	if(s[i] == '1') recurr0(i + 1, num << 1 | 1, tot);
	else if(s[i] == '?') recurr0(i + 1, num << 1, tot);
	else {
		recurr0(i + 1, num << 1, tot);
		recurr0(i + 1, num << 1 | 1, tot + 1);
	}
}

void recurrw0t(int i, int num) {
	if(i == l) {
		ans += b[num] - '0';
		return;
	} 
	if(s[i] == '?') {
		recurrw0t(i + 1, num << 1 | 1);
		recurrw0t(i + 1, num << 1);
	} else recurrw0t(i + 1, (num << 1) + (s[i] == '1'));
}
int main(int argc, char const *argv[]) {
	ios_base::sync_with_stdio(0);
	cin.tie(0);

	cin >> l >> q >> b;
	for(int i = 0; i < (1 << l); i++) {
		dp[i] = dp2[i] = b[i] - '0';
	}
	for(int i = 0; i < l; i++) {
		for(int j = 0; j < (1 << l); j++) {
			if(j >> i & 1) 
				dp[j] += dp[j ^ (1 << i)];
		}
	}
	for(int i = 0; i < l; i++) {
		for(int j = 0; j < (1 << l); j++) {
			if(~j >> i & 1) 
				dp2[j] += dp2[j | (1 << i)];
		}
	}

	while(q--) {
		cin >> s; 
		int n0 = 0, n1 = 0, nw0t = 0; 
		for(char c : s) {
			n0 += c == '0';
			n1 += c == '1';
			nw0t += c == '?';
		}
		if(n1 == 0) {
			int num = 0;
			for(char c : s) num = (num << 1) + (c == '?');
			cout << dp[num] << endl;
		} else if(nw0t == 0) {
			int num = 0;
			for(char c : s) num = (num << 1) + (c == '1');
			cout << b[num] << endl;
		} else {
			ans = 0;
			if(nw0t <= n1 && nw0t <= n0) recurrw0t(0, 0);
			else if(n1 <= nw0t && n1 <= n0) recurr1(0, 0, 0);
			else recurr0(0, 0, 0);
			cout << ans << endl;
		}
	}
}

• Subtask 1: 5 / 5
• Subtask 2: 7 / 7
• Subtask 3: 0 / 10
• Subtask 4: 53 / 53
• Subtask 5: 0 / 25