Language: C++

#include <bits/stdc++.h>
#include<atcoder/all>
using namespace std;
using namespace atcoder;

//入出力高速化
struct hishimochi{
    hishimochi(){
        ios::sync_with_stdio(false);
        cin.tie(nullptr);
        cout<<fixed<<setprecision(10);
    }
};
hishimochi Hishimochi;

//型名
using ll=long long;
using ull=unsigned long long;
using ld=long double;
using pll=pair<long long,long long>;
using vl=vector<long long>;
using vvl=vector<vector<long long>>;
using vvvl=vector<vector<vector<long long>>>;
using vi=vector<int>;
using vvi=vector<vector<int>>;
using vvvi=vector<vector<vector<int>>>;
using vc=vector<char>;
using vvc=vector<vector<char>>;
using vs=vector<string>;
using vb=vector<bool>;
using vvb=vector<vector<bool>>;
using vp=vector<pair<long long,long long>>;
using Lqueue=priority_queue<long long>;
using Squeue=priority_queue<long long,vector<long long>,greater<long long>>;

//定数
const int MOD1=1000000007;
const int MOD2=998244353;
const long double PI=3.1415926535897932;
const long long MAXLL=9223372036854775807;
const int MAXI=2147483647;
const long long INF=2305843009213693951;
const int inf=1073741789;
const long double eps=0.000000001;
const int dx[]={0,1,0,-1,1,-1,1,-1};
const int dy[]={1,0,-1,0,1,1,-1,-1};

//マクロ
#define overload3(_1,_2,_3,name,...) name
#define rep1(n) for(int _=0;_<(n);_++)
#define rep2(i,n) for(int i=0;i<(n);i++)
#define rep3(i,s,n) for(long long i=(s);i<(n);i++)
#define rep(...) overload3(__VA_ARGS__,rep3,rep2,rep1)(__VA_ARGS__)
#define bitrep1(n) for(int _=0;_<(1LL<<(n));_++)
#define bitrep2(i,n) for(int i=0;i<(1LL<<(n));i++)
#define bitrep3(i,s,n) for(int i=(s);i<(1LL<<(n));i++)
#define bitrep(...) overload3(__VA_ARGS__,bitrep3,bitrep2,bitrep1)(__VA_ARGS__)
#define rrep0(n) for(int i=(n)-1;i>=0;i--)
#define rrep1(i,n) for(int i=(n)-1;i>=0;i--)
#define rrep2(i,s,n) for(long long i=(n-1);i>=(s);i--)
#define rrep(...) overload3(__VA_ARGS__,rrep2,rrep1,rrep0)(__VA_ARGS__)
#define rbf(a,x) for(auto& a:x)
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()
#define bitcheck(bit,i) (bit)&(1LL<<(i))
#define Maxe(x) *max_element((x).begin(),(x).end())
#define Mine(x) *min_element((x).begin(),(x).end())
#define Sume(x) accumulate((x).begin(),(x).end(),0LL)
#define Size(x) ((long long)(x).size())
#define Sort(x) sort((x).begin(),(x).end())
#define rSort(x) sort((x).rbegin(),(x).rend())
#define Rev(x) reverse((x).begin(),(x).end())
#define Lin(s) getline(cin,(s))

//省略
#define fi first
#define se second
#define mp make_pair
#define mt make_tuple
#define eb emplace_back

//関数
void Yes(bool a){cout<<(a?"Yes":"No")<<endl;}
void YES(bool a){cout<<(a?"YES":"NO")<<endl;}
long long modpow(long long x,long long n,int m){long long r=1;while(n>0){if(n&1)(r*=x)%=m;(x*=x)%=m;n>>=1;}return r;}
long long Gcd(long long a,long long b){return b?Gcd(b,a%b):a;}
long long Lcm(long long a,long long b){return a/Gcd(a,b)*b;}
inline long long cutup(long long a,long long b){return (a+b-1)/b;}
inline long long popcnt(long long a){return __builtin_popcountll(a);}
template<class T,class U> inline bool chmin(T& a,U b){if(a>b){a=b;return true;}return false;}
template<class T,class U> inline bool chmax(T& a,U b){if(a<b){a=b;return true;}return false;}
template<class T> void print(T a){cout<<a<<"\n";}
template<class t> t mypow(t a,long long b){if(b==0)return 1;if(a==0)return 0;t x=1;while(b>0){if(b&1LL)x*=a;a*=a;b>>=1LL;}return x;}

ll op(ll a,ll b){
    return max(a,b);
}

ll e(){
    return 0LL;
}

signed main(){
    ll n,k;
    cin>>n>>k;
    vl A(n);
    rep(i,n)cin>>A[i];
    ll m=Maxe(A);
    segtree<ll,op,e> S(m+5);
    ll res=0;
    rep(i,n){
        ll l=max(0LL,A[n-1-i]-k);
        ll r=min(m+2,A[n-1-i]+k+1);
        ll p=S.prod(l,r);
        chmax(res,p+1);
        S.set(A[n-1-i],p+1);
    }
    print(res);
}

Compiler output:
a.cc:2:9: fatal error: atcoder/all: No such file or directory
    2 | #include<atcoder/all>
      |         ^~~~~~~~~~~~~
compilation terminated.