gadol.cpp

#include <bits/stdc++.h>

using namespace std;

#define int long long 
#define what_is(a) cout << #a << " is " << a << "\n"
#define checker(a) cout << "checker reached " << a << "\n"

inline void io(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
}

int solve(){
    int n,k;
    cin >> n >> k;
    int a[n];
    for(int i=0;i<n;i++)
        cin >> a[i];
    int lo[n];
    int hi[n];
    lo[0] = a[0]+1;
    hi[0] = a[0]+1;
    for(int i=1;i<n;i++){
        int l = a[i]+1;
        int h = a[i]+k;
        if(hi[i-1]+k-1<l || lo[i-1]-k+1>h)return 0;
        lo[i] = max(l,lo[i-1]-k+1);
        hi[i] = min(h,hi[i-1]+k-1);
    }
    if(lo[n-1]==1+a[n-1])return 1;
    return 0;
}

signed main(){
    io();
    int t;
    cin >> t;
    while(t--){
        //solve();
        cout << (solve()?"YES\n":"NO\n");
    }
    return 0;
}