A. 2-3 Moves
#include<cstdio>
#include<cstring>
#include<stdlib.h>
#include<algorithm>
#include<iostream>
#include<vector>
#include<set>
#include<string>
#include<map>
#include<queue>
#include<stack>
#include<math.h>
#define ll long long
using namespace std;
const int mod=1e9+7;
const int INF=0x3f3f3f3f;
inline int read()
{
int x=0,f=1;
char c=getchar();
while(c<'0'||c>'9'){if(c=='-')f=-1;c=getchar();}
while(c>='0'&&c<='9'){x=x*10+c-'0',c=getchar();}
return x*f;
}
void solve()
{
ll n=read();
if(n==1)
{
cout<<2<<endl;
return;
}
if(n==3)
{
cout<<1<<endl;
return;
}
ll ans=0;
if(n>4)ans+=n/3,n%=3;
if(n%2!=0)ans--,n+=3;
ans+=n/2;
printf("%lld\n",ans);
}
int main()
{
int T=read();
while(T--){solve();}
return 0;
}
B. Permutation Chain
#include<cstdio>
#include<cstring>
#include<stdlib.h>
#include<algorithm>
#include<iostream>
#include<vector>
#include<set>
#include<string>
#include<map>
#include<queue>
#include<stack>
#include<math.h>
#define ll long long
using namespace std;
const int mod=1e9+7;
const int INF=0x3f3f3f3f;
inline int read()
{
int x=0,f=1;
char c=getchar();
while(c<'0'||c>'9'){if(c=='-')f=-1;c=getchar();}
while(c>='0'&&c<='9'){x=x*10+c-'0',c=getchar();}
return x*f;
}
const int N=110;
int a[N];
void solve()
{
int n=read();
for(int i=1;i<=n;i++)a[i]=i;
printf("%d\n",n);
for(int i=1;i<=n;i++)printf("%d ",a[i]);
printf("\n");
for(int i=1;i<=n-1;i++)
{
swap(a[i],a[i+1]);
for(int j=1;j<=n;j++)printf("%d ",a[j]);
printf("\n");
}
}
int main()
{
int T=read();
while(T--){solve();}
return 0;
}
C. Robot in a Hallway
#include<cstdio>
#include<cstring>
#include<stdlib.h>
#include<algorithm>
#include<iostream>
#include<vector>
#include<set>
#include<string>
#include<map>
#include<queue>
#include<stack>
#include<math.h>
#define ll long long
using namespace std;
const int mod=1e9+7;
const int INF=0x3f3f3f3f;
inline int read()
{
int x=0,f=1;
char c=getchar();
while(c<'0'||c>'9'){if(c=='-')f=-1;c=getchar();}
while(c>='0'&&c<='9'){x=x*10+c-'0',c=getchar();}
return x*f;
}
const int N=2e5+10;
ll a[2][N];
ll f[2][N];
void solve()
{
memset(f,0,sizeof(f));
int n=read();
for(int i=0;i<2;i++)
for(int j=0;j<=n-1;j++)scanf("%lld",&a[i][j]);
a[0][0]=-1;
for(int i=n-1;i>=0;i--)
{
for(int j=0;j<=1;j++)
{
f[j][i]=max(a[j][i]+1,f[j][i+1]-1);
int p;
if(j==0)p=1;
else p=0;
f[j][i]=max(f[j][i],a[p][i]-2*n+2*i+2);
}
}
ll ans=1e18,fuck=0;
int x=0,y=0;
for(int i=0;i<n;i++)
{
ll mx=max(fuck,f[x][y])+2*(n-i)-1;
ans=min(ans,mx);
if(x==0)x=1;
else x=0;
fuck=max(a[x][y]+1,fuck+1);
y++;
if(y==n)ans=min(ans,fuck);
else fuck=max(a[x][y]+1,fuck+1);
}
printf("%lld\n",ans);
}
int main()
{
int T=read();
while(T--){solve();}
return 0;
}
D. Chip Move
void solve(){
cin >> n >> k;
f[k][0] = 1;
for(int j = 0, ff = 0; j * j <= 2 * n; j ++, ff ^= 1)
{
for(int i = 0; i <= n; i ++)
f[i][ff ^ 1] = 0;
for(int i = 1; i <= n; i ++)
if(i - j - k > 0)
{
(f[i][ff] += f[i - j -k][ff]) %= Mod;
if(i - j - k > 0)(f[i][ff ^ 1]+=f[i - j - k - 1][ff]) %= Mod;
}
for(int i = 1; i <= n; i ++){
(ans[i] += f[i][ff]) %= Mod;
}
}
for(int i = 1; i <= n; i ++){
cout << ans[i] % Mod << " ";
}
}