AtCoder Beginner Contest 209

AtCoder Beginner Contest 209

A - Counting

#pragma GCC optimize(2)
#pragma GCC optimize(3,"Ofast","inline")
#include 
#define inf 0x7fffffff
//#define ll long long
#define int long long
//#define double long double
#define re int
#define void inline void
#define eps 1e-8
//#define mod 1e9+7
#define ls(p) p<<1
#define rs(p) p<<1|1
#define pi acos(-1.0)
#define pb push_back
#define P pair < int , int >
#define mk make_pair
using namespace std;
const int mod=998244353;
const int M=1e8+5;
const int N=1e6+5;//?????????? 4e8
int x,y;
void solve()
{
	cin>>x>>y;
	
	cout<<max((int)0,y-x+1);
}
signed main()
{
    int T=1;
//    cin>>T;
    for(int index=1;index<=T;index++)
    {
//    	printf("Case #%d: ",index);
        solve();
//        puts("");
    }
    return 0;
}
/*







*/

B - Can you buy them all?

#pragma GCC optimize(2)
#pragma GCC optimize(3,"Ofast","inline")
#include 
#define inf 0x7fffffff
//#define ll long long
#define int long long
//#define double long double
#define re int
#define void inline void
#define eps 1e-8
//#define mod 1e9+7
#define ls(p) p<<1
#define rs(p) p<<1|1
#define pi acos(-1.0)
#define pb push_back
#define P pair < int , int >
#define mk make_pair
using namespace std;
const int mod=998244353;
const int M=1e8+5;
const int N=1e6+5;//?????????? 4e8
int n,m;
void solve()
{
	cin>>n>>m;
	int sum=0;
	for(re i=1;i<=n;i++)
	{
		int x;
		scanf("%lld",&x);
		sum+=x;
	}
	sum-=n/2;
	if(sum<=m)  puts("Yes");
	else  puts("No");
}
signed main()
{
    int T=1;
//    cin>>T;
    for(int index=1;index<=T;index++)
    {
//    	printf("Case #%d: ",index);
        solve();
//        puts("");
    }
    return 0;
}
/*







*/

C - Not Equal

#pragma GCC optimize(2)
#pragma GCC optimize(3,"Ofast","inline")
#include 
#define inf 0x7fffffff
//#define ll long long
#define int long long
//#define double long double
#define re int
#define void inline void
#define eps 1e-8
//#define mod 1e9+7
#define ls(p) p<<1
#define rs(p) p<<1|1
#define pi acos(-1.0)
#define pb push_back
#define P pair < int , int >
#define mk make_pair
using namespace std;
const int mod=1e9+7;
const int M=1e8+5;
const int N=1e6+5;//?????????? 4e8
int n;
int a[N],sum=1;
void solve()
{
	cin>>n;
	for(re i=1;i<=n;i++)  scanf("%lld",&a[i]);
	sort(a+1,a+n+1);
	for(re i=1;i<=n;i++)  sum=sum*(a[i]-(i-1))%mod;
	cout<<sum;
}
signed main()
{
    int T=1;
//    cin>>T;
    for(int index=1;index<=T;index++)
    {
//    	printf("Case #%d: ",index);
        solve();
//        puts("");
    }
    return 0;
}
/*







*/

D - Collision

#pragma GCC optimize(2)
#pragma GCC optimize(3,"Ofast","inline")
#include 
#define inf 0x7fffffff
//#define ll long long
#define int long long
//#define double long double
#define re int
#define void inline void
#define eps 1e-8
//#define mod 1e9+7
#define ls(p) p<<1
#define rs(p) p<<1|1
#define pi acos(-1.0)
#define pb push_back
#define P pair < int , int >
#define mk make_pair
using namespace std;
const int mod=1e9+7;
const int M=1e8+5;
const int N=1e6+5;//?????????? 4e8
struct node
{
	int ver,edge,next;
}e[N];
int tot,head[N];
int f[N][64],t;
int n,q,d[N];
void add(int x,int y)
{
	e[++tot].ver=y;
	e[tot].next=head[x];
	head[x]=tot;
}
void addedge(int x,int y)
{
	add(x,y);add(y,x);
}
void bfs()
{
	queue < int > q;
	q.push(1);
	d[1]=1; 
	while(q.size())
	{
		int x=q.front();q.pop();
		for(re i=head[x];i;i=e[i].next)
		{
			int y=e[i].ver;
			if(d[y])  continue;
			d[y]=d[x]+1;
			f[y][0]=x;
			for(re j=1;j<=t;j++)  f[y][j]=f[f[y][j-1]][j-1];
			q.push(y);
		}
	}
}
int lca(int x,int y)
{
	if(d[x]>d[y])   swap(x,y);
	for(re i=t;i>=0;i--)  if(d[f[y][i]]>=d[x])  y=f[y][i];
	if(x==y)  return x;
	for(re i=t;i>=0;i--)  if(f[x][i]!=f[y][i])  x=f[x][i],y=f[y][i];
	return f[x][0];
}
void solve()
{
	cin>>n>>q;
	t=(int)(log(n)/log(2))+1;
	for(re i=1;i<n;i++)
	{
		int x,y;
		scanf("%lld%lld",&x,&y);
		addedge(x,y);
	} 
	bfs();
	while(q--)
	{
		int x,y;
		scanf("%lld%lld",&x,&y);
		int LCA=lca(x,y);
		int z=d[x]+d[y]-2*d[LCA];
		if(z&1)  puts("Road");
		else  puts("Town");
	}
}
signed main()
{
    int T=1;
//    cin>>T;
    for(int index=1;index<=T;index++)
    {
//    	printf("Case #%d: ",index);
        solve();
//        puts("");
    }
    return 0;
}
/*







*/

E - Shiritori

坑点1、字母可以大写！！！！

坑点2、反向建图！！！！

在注意一下剪枝就行了

#pragma GCC optimize(2)
#pragma GCC optimize(3,"Ofast","inline")
#include 
#define inf 0x7fffffff
//#define ll long long
//#define int long long
//#define double long double
#define re int
#define void inline void
#define eps 1e-8
//#define mod 1e9+7
#define ls(p) p<<1
#define rs(p) p<<1|1
#define pi acos(-1.0)
#define pb push_back
#define P pair < int , int >
#define mk make_pair
using namespace std;
const int mod=1e9+7;
const int M=2e6+5;
const int N=2e6+5;//?????????? 4e8
char s[M];
struct node
{
	int ver,next;
}e[M];
int tot,head[M];
void add(int x,int y)
{
	e[++tot].ver=y;
	e[tot].next=head[x];
	head[x]=tot;
}
int n;
int d[N],a[N],in[N];
int id(char c)
{
	if(c<='Z'&&c>='A')  return c-'A'+26;
	return c-'a';
}
int get(char a,char b,char c)
{
	return id(a)*52*52+id(b)*52+id(c);
}
void dfs(int x)
{
	d[x]=2;
	for(re i=head[x];i;i=e[i].next)
	{
		int y=e[i].ver;
		if(d[y])  continue;
		d[y]=1;
		for(re j=head[y];j;j=e[j].next)
		{
			int z=e[j].ver;
			--in[z];
			if(!in[z])  dfs(z);
		}
	}
}
void solve()
{
	cin>>n;
	for(re i=1;i<=n;i++)
	{
		scanf("%s",s);
		int len=strlen(s);
		int x=get(s[0],s[1],s[2]);
		int y=get(s[len-3],s[len-2],s[len-1]);
		in[x]++;
		add(y,x);
		a[i]=y;
	}
	for(re i=0;i<M;i++)  if(!in[i])  dfs(i);
	for(re i=1;i<=n;i++)  if(d[a[i]]==1)  puts("Aoki");
	else if(d[a[i]])  puts("Takahashi");
	else  puts("Draw");
}
signed main()
{
    int T=1;
//    cin>>T;
    for(int index=1;index<=T;index++)
    {
//    	printf("Case #%d: ",index);
        solve();
//        puts("");
    }
    return 0;
}
/*







*/