RT，第二个样例只有第三个测试点没过。

#include<bits/stdc++.h>
#define int long long
#define mid (l+(r-l>>1))
#define ls (mid<<1)
#define rs (mid<<1|1)
using namespace std;
const int N=6e5+5,inf=1e9;
int c,t,n,m,k,d,ans;
int b[N],L,R,K;
struct node{
	int l,r,w;
	bool operator<(const node &t)
	const{return r==t.r?l<t.l:r<t.r;}
}nd[N];
struct Tree{
	int w,fl;
}tr[N<<1];
inline void chgw(int x,int k){tr[x].w+=k,tr[x].fl+=k;}
inline void pushdown(int l,int r,int id){
	int x=tr[id].fl;
	if(x)chgw(ls,x),chgw(rs,x),tr[id].fl=0;
}
void upd(int l,int r,int id){
	if(L<=l&&r<=R)return chgw(id,K);
	pushdown(l,r,id);
	if(L<=mid)upd(l,mid,ls);
	if(mid<R)upd(mid+1,r,rs);
	tr[id].w=max(tr[ls].w,tr[rs].w);
}
signed main(){
    // freopen("run2.in","r",stdin);
    // freopen("run.out","w",stdout);
    ios::sync_with_stdio(0);
    cin.tie(0),cout.tie(0);
    cin>>c>>t;while(t--){
		cin>>n>>m>>k>>d;n=0;
		for(int i=1; i<=m; ++i)
			cin>>nd[i].r>>nd[i].l>>nd[i].w,
			nd[i].l=nd[i].r-nd[i].l+1,
			b[++n]=nd[i].l,b[++n]=nd[i].r;
		for(int i=1,t=n; i<=t; ++i)
		    b[++n]=b[i]-1,b[++n]=b[i]+1;
		sort(b+1,b+1+n);
        n=unique(b+1,b+1+n)-b-1;
		for(int i=1; i<=m; ++i)
			nd[i].l=lower_bound(b+1,b+1+n,nd[i].l)-b,
			nd[i].r=lower_bound(b+1,b+1+n,nd[i].r)-b;
        sort(nd+1,nd+1+m);
		for(int i=1,t; i<=m; ++i){
			t=lower_bound(b+1,b+1+n,b[nd[i].r]-k+1)-b;
			for(int j=max(nd[i-1].r+1,t); j<=nd[i].r; ++j){
				L=R=j+1,K=max(tr[1].w,0ll);if(R<=n)upd(1,n,1);
				L=t,R=j-1,K=-d*(b[j]-b[j-1]);
				if(L<=R)upd(1,n,1);
				L=R=j,K=-d,upd(1,n,1);
                ans=max(ans,tr[1].w);
			}
			L=t,R=nd[i].l,K=nd[i].w;if(L<=R)upd(1,n,1);
            ans=max(ans,tr[1].w);
		}cout<<ans<<'\n';ans=0;++n;
		memset(tr,0,sizeof*tr*n<<1);
	}
    return 0;
}