Submission #291042

#	Time	Username	Problem	Language	Result	Execution time	Memory
291042		PeppaPig	"The Lyuboyn" code (IZhO19_lyuboyn)	C++14	100 / 100	602 ms	7704 KiB

lyuboyn

#include <bits/stdc++.h>

using namespace std;

const int N = 1 << 19;

int n, k, t, s;
mt19937 rng(time(NULL));

void print(int val) {
	vector<int> vec;
	for(int i = 0; i < n; i++, val >>= 1)
		vec.emplace_back(val & 1);
	reverse(vec.begin(), vec.end());
	for(int x : vec) printf("%d", x);
	printf("\n");
}

int chk[N], ans[N];
vector<int> base;

bool is_basis() {
	vector<int> mat(base.begin(), base.begin() + n);
	for(int i = n - 1; ~i; i--) {
		int val = -1;
		for(int x : mat) if(x >> i & 1) val = x;
		if(val == -1) return false;
		for(int &x : mat) if(x != val && (x >> i & 1))
			x ^= val;	
	}
	return true;
}

int main() {
	char input[100];
	scanf("%d %d %d %s", &n, &k, &t, input);
	if(k % 2 == 0) return !printf("-1\n");

	for(int i = 0; input[i] != '\0'; i++)
		s = (s << 1) + (input[i] == '1');

	for(int i = 0; i < (1 << n); i++) if(__builtin_popcount(i) == k)
		base.emplace_back(i);

	while(true) {
		shuffle(base.begin(), base.end(), rng);
		if(!is_basis()) continue;

		ans[0] = s;
		int ptr = 1, valid = 1;
		for(int j = 0; j < n; j++) for(int i = ptr - 1; ~i; i--) {
			ans[ptr] = ans[i] ^ base[j];
			if(!chk[ans[ptr]]) chk[ans[ptr]] = 1;
			else {
				valid = 0;
				break;
			}
			++ptr;
		}

		if(valid) {
			printf("%d\n", (1 << n));
			for(int i = 0; i < (1 << n); i++) print(ans[i]);
			exit(0);
		} else for(int i = 0; i < (1 << n); i++) chk[ans[i]] = 0;
	}

	return 0;
}

Compilation message (stderr)

lyuboyn.cpp: In function 'int main()':
lyuboyn.cpp:36:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   36 |  scanf("%d %d %d %s", &n, &k, &t, input);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 0
• Subtask 2: 5 / 5
• Subtask 3: 3 / 3
• Subtask 4: 11 / 11
• Subtask 5: 15 / 15
• Subtask 6: 18 / 18
• Subtask 7: 31 / 31
• Subtask 8: 17 / 17