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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
#91274#6137. Sub-cycle Graphs8194272WA 136ms5728kbC++142.0kb2023-03-28 09:44:092023-03-28 09:44:12

Judging History

你现在查看的是最新测评结果

  • [2023-08-10 23:21:45]
  • System Update: QOJ starts to keep a history of the judgings of all the submissions.
  • [2023-03-28 09:44:12]
  • 评测
  • 测评结果:WA
  • 用时:136ms
  • 内存:5728kb
  • [2023-03-28 09:44:09]
  • 提交

answer

#include<iostream>
#include<algorithm>
#include<cstring>
#include<cstdio>
#include<bitset>
#include<random>
#include<cmath>
#include<ctime>
#include<queue>
#include<map>
#include<set>

#define int long long
#define fi first
#define se second
#define max Max
#define min Min
#define abs Abs
#define lc (x<<1)
#define rc (x<<1|1)
#define mid ((l+r)>>1)
#define pb(x) push_back(x)
#define lowbit(x) ((x)&(-(x)))
#define fan(x) ((((x)-1)^1)+1)
#define mp(x,y) make_pair(x,y)
#define clr(f,n) memset(f,0,sizeof(int)*(n))
#define cpy(f,g,n) memcpy(f,g,sizeof(int)*(n))
#define SZ(x) ((int)(x.size()))
#define INF 0x3f3f3f3f

using namespace std;

inline int read()
{
	int ans=0,f=1;
	char c=getchar();
	while(c>'9'||c<'0'){if(c=='-')f=-1;c=getchar();}
	while(c>='0'&&c<='9'){ans=(ans<<1)+(ans<<3)+c-'0';c=getchar();}
	return ans*f;
}

inline void write(int x)
{
	if(x<0) putchar('-'),x=-x;
	if(x/10) write(x/10);
	putchar((char)(x%10)+'0');
}

template<typename T>inline T Abs(T a){return a>0?a:-a;};
template<typename T,typename TT>inline T Min(T a,TT b){return a<b?a:b;}
template<typename T,typename TT> inline T Max(T a,TT b){return a<b?b:a;}

const int N=1e5+5,mod=1e9+7;
int t,n,m,jc[N],inv[N],pw[N];

inline int q_pow(int a,int b)
{
	int c=1;
	while(b)
	{
		if(b&1) c=a*c%mod;
		a=a*a%mod;b>>=1;
	}
	return c;
}

inline void init(int x)
{
	jc[0]=1;pw[0]=1;
	for(int i=1;i<=x;++i)
	{
		jc[i]=jc[i-1]*i%mod;
		pw[i]=pw[i-1]*(mod+1)/2%mod;
	}
	inv[x]=q_pow(jc[x],mod-2);
	for(int i=x-1;i>=0;--i)
		inv[i]=inv[i+1]*(i+1)%mod;
}

inline int C(int n,int m)
{
	return n<m?0:jc[n]*inv[m]%mod*inv[n-m]%mod;
}

signed main()
{
	init(100000);
	t=read();
	while(t--)
	{
		n=read();m=read();
		if(m>n) write(0);
		else if(m==n) write(jc[n-1]);
		else
		{
			int ans=0;
			for(int i=0;i<=n-m;++i)
				ans=(ans+C(n,i)*C(m-1,n-m-i-1)%mod*jc[n-i]%mod*inv[n-m-i]%mod*pw[n-m-i])%mod;
			write(ans);
		}
		puts("");
	}
	return 0;
}

詳細信息

Test #1:

score: 100
Accepted
time: 0ms
memory: 5728kb

input:

3
4 2
4 3
5 3

output:

15
12
90

result:

ok 3 number(s): "15 12 90"

Test #2:

score: -100
Wrong Answer
time: 136ms
memory: 5724kb

input:

17446
3 0
3 1
3 2
3 3
4 0
4 1
4 2
4 3
4 4
5 0
5 1
5 2
5 3
5 4
5 5
6 0
6 1
6 2
6 3
6 4
6 5
6 6
7 0
7 1
7 2
7 3
7 4
7 5
7 6
7 7
8 0
8 1
8 2
8 3
8 4
8 5
8 6
8 7
8 8
9 0
9 1
9 2
9 3
9 4
9 5
9 6
9 7
9 8
9 9
10 0
10 1
10 2
10 3
10 4
10 5
10 6
10 7
10 8
10 9
10 10
11 0
11 1
11 2
11 3
11 4
11 5
11 6
11 7
11...

output:

0
3
3
2
0
6
15
12
6
0
10
45
90
60
24
0
15
105
375
630
360
120
0
21
210
1155
3465
5040
2520
720
0
28
378
2940
13545
35280
45360
20160
5040
0
36
630
6552
42525
170100
393120
453600
181440
40320
0
45
990
13230
114345
643545
2286900
4762800
4989600
1814400
362880
0
55
1485
24750
273735
2047815
10239075
...

result:

wrong answer 1st numbers differ - expected: '1', found: '0'