/*input
7 8 8 13
0
4
-9
4
-2
3
10
-9
1 4 8
3 5 -2
3 3 9
1 7 4
3 5 -1
5 6 3
4 4 9
6 7 -10
*/
#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#pragma GCC optimize("unroll-loops,no-stack-protector")
//order_of_key #of elements less than x
// find_by_order kth element
#define ll long long
#define ld long double
#define pii pair<double,double>
typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> indexed_set;
#define f first
#define s second
#define pb push_back
#define REP(i,n) for(int i=0;i<n;i++)
#define REP1(i,n) for(int i=1;i<=n;i++)
#define FILL(n,x) memset(n,x,sizeof(n))
#define ALL(_a) _a.begin(),_a.end()
#define sz(x) (int)x.size()
#define SORT_UNIQUE(c) (sort(c.begin(),c.end()), c.resize(distance(c.begin(),unique(c.begin(),c.end()))))
#define MP make_pair
const ll INF64=4e12;
const int INF=0x3f3f3f3f;
const ll MOD=1e9+7;
const ld PI=acos(-1);
const ld eps=1e-9;
#define lowb(x) x&(-x)
#define MNTO(x,y) x=min(x,(__typeof__(x))y)
#define MXTO(x,y) x=max(x,(__typeof__(x))y)
ll mult(ll a,ll b){
return ((a%MOD)*(b%MOD))%MOD;
}
ll mypow(ll a,ll b){
if(b<=0) return 1;
ll res=1LL;
while(b){
if(b&1){
res=(res*a)%MOD;
}
a=(a*a)%MOD;
b>>=1;
}
return res;
}
const ll maxn=2e5+5;
const ll maxlg=__lg(maxn)+2;
#define int ll
int arr[maxn];
struct node{
ll mx,lazy=0;
}seg[4*maxn];
node pull(node a,node b){
node x;
x.mx=max(a.mx,b.mx);
return x;
}
void pushdown(int idx,int l,int r){
if(!seg[idx].lazy) return;
seg[idx].mx+=seg[idx].lazy;
if(l==r){
seg[idx].lazy=0;
return;
}
seg[idx*2].lazy+=seg[idx].lazy;
seg[idx*2+1].lazy+=seg[idx].lazy;
seg[idx].lazy=0;
}
void build(int idx,int l,int r){
if(l==r){
seg[idx].mx=arr[l];
return;
}
int mid=(l+r)/2;
build(idx*2,l,mid);
build(idx*2+1,mid+1,r);
seg[idx]=pull(seg[idx*2],seg[idx*2+1]);
}
void upd(int idx,int l,int r,int ql,int qr,int x){
pushdown(idx,l,r);
if(r<ql or l>qr) return;
if(ql<=l and r<=qr){
seg[idx].lazy+=x;
pushdown(idx,l,r);
return;
}
int mid=(l+r)/2;
upd(idx*2,l,mid,ql,qr,x);
upd(idx*2+1,mid+1,r,ql,qr,x);
seg[idx]=pull(seg[idx*2],seg[idx*2+1]);
}
ll query(int idx,int l,int r,int ql,int qr){
if(r<ql or l>qr) return -INF64;
pushdown(idx,l,r);
if(ql<=l and r<=qr){
return seg[idx].mx;
}
int mid=(l+r)/2;
return max(query(idx*2,l,mid,ql,qr),query(idx*2+1,mid+1,r,ql,qr));
}
int n;
ll get(int i){
return query(1,0,n-1,i,i);
}
ll ssum=0,tsum=0;
int32_t main(){
ios::sync_with_stdio(false),cin.tie(0);
int q,s,t;
cin>>n>>q>>s>>t;
++n;
REP(i,n){
cin>>arr[i];
if(i){
if(arr[i]>arr[i-1]) ssum+=(arr[i]-arr[i-1]);
else tsum+=(arr[i-1]-arr[i]);
}
}
build(1,0,n-1);
REP(i,q){
int l,r,x;
cin>>l>>r>>x;
int tl=get(l),tl1=get(l-1);
if(tl>tl1) ssum-=(tl-tl1);
else tsum-=(tl1-tl);
if(r!=(n-1)){
tl1=get(r),tl=get(r+1);
if(tl>tl1) ssum-=(tl-tl1);
else tsum-=(tl1-tl);
}
upd(1,0,n-1,l,r,x);
tl=get(l),tl1=get(l-1);
if(tl>tl1) ssum+=(tl-tl1);
else tsum+=(tl1-tl);
if(r!=(n-1)){
tl1=get(r),tl=get(r+1);
if(tl>tl1) ssum+=(tl-tl1);
else tsum+=(tl1-tl);
}
//cout<<tsum<<' '<<ssum<<' ';
cout<<tsum*t-ssum*s<<'\n';
}
}
