Language: C++

//g++ -std=c++14 test.cpp -o test.out
 
#include <string.h>
#include <stdlib.h>
#include <math.h>
#include <cassert>
#include <algorithm>
#include <functional>
#include <iostream>
#include <iomanip>
#include <vector>
#include <queue>
#include <stack>
#include <map> 
#include <unordered_map> 
#include <utility>
#include <limits.h>
#include <bitset>
#include <set>
using namespace std;
 
#define LL long long int
const LL INF = (1LL<<60);
const int INF_INT = 2147483647-1e6-1;
const LL mod = 1000000007ll;
const int mod_int = 1000000007;

//引用元：https://drken1215.hatenablog.com/entry/2020/09/27/080300
template<class Monoid> struct SegmentTree {
    using Func = function<Monoid(Monoid, Monoid)>;
    const Func F;
    const Monoid UNITY;
    int SIZE_R;
    vector<Monoid> dat;
    
    SegmentTree(int n, const Func f, const Monoid &unity): F(f), UNITY(unity) { init(n); }
    void init(int n) {
        SIZE_R = 1;
        while (SIZE_R < n) SIZE_R *= 2;
        dat.assign(SIZE_R * 2, UNITY);
    }
    
    /* set, a is 0-indexed */
    void set(int a, const Monoid &v) { dat[a + SIZE_R] = v; }
    void build() {
        for (int k = SIZE_R - 1; k > 0; --k)
            dat[k] = F(dat[k*2], dat[k*2+1]);
    }
    
    /* update a, a is 0-indexed */
    void update(int a, const Monoid &v) {
        //まず最下段の、元の配列に相当する箇所を更新
        int k = a + SIZE_R;
        dat[k] = v;
        //登りながら更新
        while (k >>= 1) dat[k] = F(dat[k*2], dat[k*2+1]);
    }
    
    /* query [a, b), a and b are 0-indexed */
    Monoid query(int a, int b) {
        Monoid vleft = UNITY, vright = UNITY;
        for (int left = a + SIZE_R, right = b + SIZE_R; left < right; left >>= 1, right >>= 1) {
            if (left & 1) vleft = F(vleft, dat[left++]);
            if (right & 1) vright = F(dat[--right], vright);
        }                                                                                                              
        return F(vleft, vright);
    }
    inline Monoid operator [] (int a) { return dat[a + SIZE_R]; }
    
    /* debug */
    void print() {
        for (int i = 0; i < SIZE_R; ++i) {
            cout << (*this)[i];
            if (i != SIZE_R-1) cout << ",";
        }
        cout << endl;
    }
};

LL N,K;
LL A[300000];

LL ans;

void solve(){
    //ラストがiで終わるような数列の最大の長さをdp[i]とする
    const LL MAX_A =　300000；
    auto func = [&](LL a,LL b) { return max(a,b); };
    SegmentTree<LL> st(MAX_A+1,func,0);
    for(int i=0;i<N;i++){
        LL left = max(0LL,A[i]-K);
        LL right = min(MAX_A,A[i]+K);
        LL cand = st.query(left,right+1);
        st.update(A[i],cand+1);
    }
    ans = st.query(1,MAX_A+1);
}
 
int main(){
	cin >> N >> K;
    for(int i=0;i<N;i++) cin >> A[i];
 
    solve();

	cout << ans << endl;
    return 0;
}

Compiler output:
a.cc:87:21: error: extended character 　 is not valid in an identifier
   87 |     const LL MAX_A =　300000；
      |                     ^
a.cc: In function 'void solve()':
a.cc:87:21: error: '\U00003000300000\U0000ff1b' was not declared in this scope
   87 |     const LL MAX_A =　300000；
      |                     ^~~~~~~~~~
a.cc:89:32: error: 'func' was not declared in this scope
   89 |     SegmentTree<LL> st(MAX_A+1,func,0);
      |                                ^~~~