Codeforces Round #663 (Div. 2)

link

Problems

#	Name
A	Suborrays
B	Fix You
C	Cyclic Permutations
D	505
E	Pairs of Pairs

Solution

A

#include<set>
#include<map>
#include<ctime>
#include<queue>
#include<stack>
#include<vector>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<iostream>
#include<algorithm>
#define rint register int
typedef long long LL;
typedef unsigned long long ULL;
using namespace std;
int T,n;
int main()
{
//	freopen("1.in","r",stdin);
	scanf("%d",&T);
	while(T--) {
		scanf("%d",&n);
		for(int i=1;i<=n;i++) 
			printf("%d ",i);
		printf("\n");
	}
	return 0;
}

B

#include<set>
#include<map>
#include<ctime>
#include<queue>
#include<stack>
#include<vector>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<iostream>
#include<algorithm>
#define rint register int
typedef long long LL;
typedef unsigned long long ULL;
using namespace std;
const int N=256;
int T,n,m;
char a[N][N];
int main()
{
//	freopen("1.in","r",stdin);
	int i;
	scanf("%d",&T);
	while(T--) {
		scanf("%d%d",&n,&m);
		int ans=0;
		for(i=1;i<=n;i++)
			scanf("%s",a[i]+1);
		for(i=1;i<=n;i++) 
			ans+=(a[i][m]=='R');
		for(i=1;i<=m;i++) 
			ans+=(a[n][i]=='D');
		cout<<ans<<endl;
	}
	return 0;
}

C

#include<set>
#include<map>
#include<ctime>
#include<queue>
#include<stack>
#include<vector>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<iostream>
#include<algorithm>
#define rint register int
typedef long long ULL;
using namespace std;
const ULL MOD=1e9+7;
ULL n;
ULL p=1,k=1;
int main()
{
	scanf("%lld",&n);
	for(ULL i=1;i<=n;i++) 
		p=p*i%MOD;
	for(ULL i=1;i<=n-1;i++) 
		k=k*2%MOD;
	printf("%lld",((p-k)%MOD+MOD)%MOD);
	return 0;
}

• link:https://oeis.org/search?q=16%2C104%2C688%2C4976&language=english&go=Search
• 再也不用 unsigned long long 了。(除了Hash)。