Codeforces Round #485 (Div. 1) C. AND Graph

注意到能与 \(x\) 连边的 \(y\)\(x\) 的补集的子集
那么就枚举之后dfs补集,每个全集再减去一位即可,这样是有传递性,保证一个连通块的所有数都能遍历到
这种位运算的可以通过增一位减一位得到传递性!!!

#include <bits/stdc++.h>
#define pb push_back
#define fi first
#define se second
#define pii pair<int, int>
#define pli pair<ll, int>
#define lp p << 1
#define rp p << 1 | 1
#define mid ((l + r) / 2)
#define lowbit(i) ((i) & (-i))
typedef long long ll;
typedef unsigned long long ull;
typedef double db;
#define rep(i,a,b) for(int i=(a);i<(b);i++)
#define per(i,a,b) for(int i=((b)-1);i>=(a);i--)
#define Edg int ccnt=1,head[N],to[E],ne[E];void addd(int u,int v){to[++ccnt]=v;ne[ccnt]=head[u];head[u]=ccnt;}void add(int u,int v){addd(u,v);addd(v,u);}
#define Edgc int ccnt=1,head[N],to[E],ne[E],c[E];void addd(int u,int v,int w){to[++ccnt]=v;ne[ccnt]=head[u];c[ccnt]=w;head[u]=ccnt;}void add(int u,int v,int w){addd(u,v,w);addd(v,u,w);}
#define es(u,i,v) for(int i=head[u],v=to[i];i;i=ne[i],v=to[i])
const int MOD = 1e9 + 7;
void M(int &x) {if (x >= MOD)x -= MOD; if (x < 0)x += MOD;}
int qp(int a, int b = MOD - 2) {int ans = 1; for (; b; a = 1LL * a * a % MOD, b >>= 1)if (b & 1)ans = 1LL * ans * a % MOD; return ans % MOD;}
template<class T>T gcd(T a, T b) { while (b) { a %= b; std::swap(a, b); } return a; }
template<class T>bool chkmin(T &a, T b) { return a > b ? a = b, 1 : 0; }
template<class T>bool chkmax(T &a, T b) { return a < b ? a = b, 1 : 0; }
char buf[1 << 21], *p1 = buf, *p2 = buf;
inline char getc() {
	return p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, 1 << 21, stdin), p1 == p2) ? EOF : *p1++;
}
inline int _() {
	int x = 0, f = 1; char ch = getc();
	while (ch < '0' || ch > '9') { if (ch == '-') f = -1; ch = getc(); }
	while (ch >= '0' && ch <= '9') { x = x * 10ll + ch - 48; ch = getc(); }
	return x * f;
}

const int N = 23;
bool vis[1 << N], seq[1 << N];
int n, m, a[1 << N], S;

void dfs(int s0) {
	if (vis[s0]) return;
	vis[s0] = 1;
	if (seq[s0]) dfs(s0 ^ S);
	rep (i, 0, n) if (s0 >> i & 1) dfs(s0 ^ (1 << i));
}

int main() {
#ifdef LOCAL
	freopen("ans.out", "w", stdout);
#endif
	n = _(), m = _();
	S = 1 << n;
	S--;
	rep (i, 1, m + 1) a[i] = _(), seq[a[i]] = 1;
	int ans = 0;
	rep (i, 1, m + 1) if (!vis[a[i]]) {
		ans++;
		vis[a[i]] = 1;
		dfs(a[i] ^ S);
	}
	printf("%d\n", ans);
#ifdef LOCAL
	printf("%.10f\n", (db)clock() / CLOCKS_PER_SEC);
#endif
	return 0;
}
posted @ 2020-03-06 19:57  Mrzdtz220  阅读(103)  评论(0)    收藏  举报