模拟一遍即可

#include<bits/stdc++.h>
using namespace std;
int a[1000005];
int main(){
    int T; cin >> T;
    while(T--){
        int n,k,d,w; cin >> n >> k >> d >> w;
        for(int i = 1;i <= n;i++) cin >> a[i];
        int cnt = 0,t = k,now = a[1],last = now + w + d;
        for(int i = 1;i <= n;i++){
            if(t > 0 && a[i] >= now && a[i] <= last) t--;
            else if(t == 0 || a[i] > last){
                cnt++;
                now = a[i];
                last = now + w + d;
                t = k - 1;
            }
        }
        cout << cnt + 1 << endl;
    }
    return 0;
}