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ID题目提交者结果用时内存语言文件大小提交时间测评时间
#423350#8729. TikvaniCrysfly0 1ms3772kbC++173.1kb2024-05-27 22:33:582024-05-27 22:33:58

Judging History

This is the latest submission verdict.

  • [2024-05-27 22:33:58]
  • Judged
  • Verdict: 0
  • Time: 1ms
  • Memory: 3772kb
  • [2024-05-27 22:33:58]
  • Submitted

answer

// what is matter? never mind. 
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("unroll-loops")
//#pragma GCC target("sse,sse2,sse3,sse4,popcnt,abm,mmx,avx,avx2") 
#include<bits/stdc++.h>
#define For(i,a,b) for(int i=(a);i<=(b);++i)
#define Rep(i,a,b) for(int i=(a);i>=(b);--i)
#define ll long long
//#define int long long
#define ull unsigned long long
#define SZ(x) ((int)((x).size()))
#define ALL(x) (x).begin(),(x).end()
using namespace std;
inline int read()
{
    char c=getchar();int x=0;bool f=0;
    for(;!isdigit(c);c=getchar())f^=!(c^45);
    for(;isdigit(c);c=getchar())x=(x<<1)+(x<<3)+(c^48);
    if(f)x=-x;return x;
}

#define mod 1000000007
struct modint{
	int x;
	modint(int o=0){x=o;}
	modint &operator = (int o){return x=o,*this;}
	modint &operator +=(modint o){return x=x+o.x>=mod?x+o.x-mod:x+o.x,*this;}
	modint &operator -=(modint o){return x=x-o.x<0?x-o.x+mod:x-o.x,*this;}
	modint &operator *=(modint o){return x=1ll*x*o.x%mod,*this;}
	modint &operator ^=(int b){
		modint a=*this,c=1;
		for(;b;b>>=1,a*=a)if(b&1)c*=a;
		return x=c.x,*this;
	}
	modint &operator /=(modint o){return *this *=o^=mod-2;}
	friend modint operator +(modint a,modint b){return a+=b;}
	friend modint operator -(modint a,modint b){return a-=b;}
	friend modint operator *(modint a,modint b){return a*=b;}
	friend modint operator /(modint a,modint b){return a/=b;}
	friend modint operator ^(modint a,int b){return a^=b;}
	friend bool operator ==(modint a,modint b){return a.x==b.x;}
	friend bool operator !=(modint a,modint b){return a.x!=b.x;}
	bool operator ! () {return !x;}
	modint operator - () {return x?mod-x:0;}
	bool operator <(const modint&b)const{return x<b.x;}
};
inline modint qpow(modint x,int y){return x^y;}

vector<modint> fac,ifac,iv;
inline void initC(int n)
{
	if(iv.empty())fac=ifac=iv=vector<modint>(2,1);
	int m=iv.size(); ++n;
	if(m>=n)return;
	iv.resize(n),fac.resize(n),ifac.resize(n);
	For(i,m,n-1){
		iv[i]=iv[mod%i]*(mod-mod/i);
		fac[i]=fac[i-1]*i,ifac[i]=ifac[i-1]*iv[i];
	}
}
inline modint C(int n,int m){
	if(m<0||n<m)return 0;
	return initC(n),fac[n]*ifac[m]*ifac[n-m];
}
inline modint sign(int n){return (n&1)?(mod-1):(1);}

#define fi first
#define se second
#define pb push_back
#define mkp make_pair
typedef pair<int,int>pii;
typedef vector<int>vi;

#define maxn 505
#define inf 0x3f3f3f3f

int n,m;

typedef bitset<maxn> bint;
struct bas{
	int cnt;
	bint t[maxn];
	void ins(bint x){
		Rep(i,m,1)
			if(x[i]){
				if(!t[i][i]) return t[i]=x,++cnt,void();
				x^=t[i];
			}
	}
}B;

vector<pii>e[maxn];
bint val[maxn];
bool vis[maxn];

void dfs(int u){
	vis[u]=1;
	for(auto [v,id]:e[u]){
		if(!vis[v]){
			val[v]=val[u],val[v].flip(id);
			dfs(v);
		}
		else {
			bint tmp=(val[u]^val[u]); tmp.flip(id);
			B.ins(tmp);
		}
	}
}

signed main()
{
	n=read(),m=read();
	For(i,1,m){
		int u=read(),v=read();
		e[u].pb(mkp(v,i));
	}
	For(u,1,n){
		For(i,1,n) vis[i]=0;
		dfs(u);
	}
	int res=m-B.cnt;
	cout<<qpow(2,res).x;
	return 0;
}
/*
6 7
2 5
2 3
3 6
2 4
1 4
1 6
1 5
*/

詳細信息

Subtask #1:

score: 0
Wrong Answer

Test #1:

score: 21
Accepted
time: 1ms
memory: 3696kb

input:

6 5
3 5
2 5
1 6
4 6
2 6

output:

32

result:

ok 1 number(s): "32"

Test #2:

score: 21
Accepted
time: 0ms
memory: 3756kb

input:

6 6
2 5
1 2
3 4
5 6
3 6
1 5

output:

32

result:

ok 1 number(s): "32"

Test #3:

score: 21
Accepted
time: 0ms
memory: 3752kb

input:

6 7
3 6
1 3
3 5
2 3
1 6
2 6
2 5

output:

16

result:

ok 1 number(s): "16"

Test #4:

score: 21
Accepted
time: 0ms
memory: 3700kb

input:

6 8
1 4
2 3
5 6
3 6
4 5
2 6
4 6
1 5

output:

32

result:

ok 1 number(s): "32"

Test #5:

score: 21
Accepted
time: 0ms
memory: 3700kb

input:

6 7
1 4
3 6
2 3
1 5
2 4
2 6
5 6

output:

64

result:

ok 1 number(s): "64"

Test #6:

score: 21
Accepted
time: 0ms
memory: 3640kb

input:

6 8
2 3
2 4
2 5
3 6
1 6
1 2
1 4
1 5

output:

32

result:

ok 1 number(s): "32"

Test #7:

score: 21
Accepted
time: 0ms
memory: 3772kb

input:

6 7
5 6
2 5
2 4
1 6
2 3
3 6
1 2

output:

32

result:

ok 1 number(s): "32"

Test #8:

score: 21
Accepted
time: 0ms
memory: 3696kb

input:

6 8
2 3
1 4
2 4
3 6
1 5
5 6
1 6
2 6

output:

64

result:

ok 1 number(s): "64"

Test #9:

score: 0
Wrong Answer
time: 0ms
memory: 3636kb

input:

6 7
2 6
4 5
1 2
3 6
3 5
1 4
5 6

output:

64

result:

wrong answer 1st numbers differ - expected: '32', found: '64'

Subtask #2:

score: 0
Skipped

Dependency #1:

0%

Subtask #3:

score: 0
Wrong Answer

Test #25:

score: 37
Accepted
time: 0ms
memory: 3716kb

input:

50 50
29 32
3 12
36 41
10 30
6 18
20 27
14 36
4 33
6 7
17 31
33 40
2 49
19 42
3 30
2 18
11 42
21 29
11 23
1 35
32 50
22 46
6 22
42 48
15 23
7 43
11 13
5 9
40 50
25 42
5 31
27 30
1 17
14 48
5 44
35 41
1 23
10 21
40 48
12 36
13 37
23 37
23 43
19 26
6 15
13 45
19 27
17 29
20 38
29 42
26 49

output:

974740338

result:

ok 1 number(s): "974740338"

Test #26:

score: 37
Accepted
time: 0ms
memory: 3696kb

input:

49 50
23 42
22 30
8 18
28 42
14 37
34 40
11 34
2 5
9 14
24 34
11 32
41 45
8 28
6 23
9 17
22 31
20 38
4 47
2 39
13 22
14 26
8 45
37 45
17 23
34 37
13 37
33 48
5 12
17 37
27 30
17 21
18 22
28 43
10 23
33 43
31 49
10 43
8 26
12 19
14 28
6 14
2 20
12 49
26 39
35 45
14 48
3 6
14 36
6 48
1 17

output:

743685088

result:

ok 1 number(s): "743685088"

Test #27:

score: 37
Accepted
time: 1ms
memory: 3628kb

input:

48 50
4 39
3 43
41 47
10 34
19 36
5 17
19 35
34 38
5 30
32 47
10 41
3 44
11 29
13 37
5 47
18 33
1 45
29 45
2 13
2 38
8 36
3 34
40 45
8 20
4 21
4 31
18 43
29 32
26 38
13 29
35 48
10 36
1 9
14 23
13 34
16 27
5 18
16 36
1 6
1 36
36 44
39 43
21 39
30 42
11 18
5 11
9 37
15 30
25 45
29 40

output:

371842544

result:

ok 1 number(s): "371842544"

Test #28:

score: 37
Accepted
time: 0ms
memory: 3760kb

input:

47 50
16 21
23 44
12 42
8 25
5 19
29 37
11 27
14 20
18 44
46 47
8 42
20 29
1 29
19 31
2 33
16 27
13 39
37 40
12 18
3 37
2 43
35 43
19 22
3 44
19 32
42 46
29 33
1 4
3 18
7 38
2 40
4 26
16 31
28 45
20 34
12 15
5 17
14 41
13 20
25 41
6 15
31 33
24 35
13 33
7 11
12 16
2 31
35 44
10 25
17 47

output:

487370169

result:

ok 1 number(s): "487370169"

Test #29:

score: 37
Accepted
time: 0ms
memory: 3712kb

input:

46 50
1 35
27 34
2 46
18 23
7 45
17 28
12 38
6 17
38 42
15 46
1 29
11 14
12 27
4 39
37 38
25 30
2 42
22 23
13 27
7 15
30 33
19 27
27 36
26 42
20 42
25 37
27 33
30 38
16 32
5 33
17 34
12 31
35 40
15 39
40 44
10 38
19 41
24 36
38 46
19 29
19 35
8 28
12 45
27 40
22 40
8 27
16 19
10 22
12 20
17 35

output:

487370169

result:

ok 1 number(s): "487370169"

Test #30:

score: 0
Wrong Answer
time: 1ms
memory: 3732kb

input:

45 50
38 45
29 43
24 38
1 44
16 22
13 21
3 7
35 45
22 33
27 38
11 26
29 32
3 15
34 36
17 34
14 33
29 35
12 13
11 18
15 41
5 45
20 41
12 27
21 39
15 34
33 42
32 42
13 44
25 37
3 4
14 25
28 34
7 14
4 41
9 27
23 35
39 45
6 29
26 30
10 35
18 43
4 12
2 9
23 40
3 40
16 43
2 28
27 45
4 35
14 35

output:

185921272

result:

wrong answer 1st numbers differ - expected: '371842544', found: '185921272'

Subtask #4:

score: 0
Skipped

Dependency #1:

0%