#include<bits/stdc++.h>
using namespace std;
#define debug(n,m) cout<<"["<<#n<<"]->"<<n<<m
#define int long long
#define all(x) x.begin(),x.end()
#define pb push_back
const int N=2e6+5;
const int mod=1e9+7;
const int inf=2e9;
struct Segtree {
vector<int> tr;
vector<int> lz;
int n;
void init(int n) {
tr.assign(4*n+1,0);
lz.assign(4*n+1,0);
this->n=n;
}
void push(int u,int l,int r) {
tr[u]+=(r-l+1)*lz[u];
if (l!=r) {
lz[u<<1]+=lz[u];
lz[u<<1|1]+=lz[u];
}
lz[u]=0;
}
void upd(int u,int l,int r,int x,int y,int k) {
push(u,l,r);
if (x>r||y<l) return;
if (l>=x&&r<=y) {
lz[u]+=k;
push(u,l,r);
return;
}
int m=l+r>>1;
upd(u<<1,l,m,x,y,k);
upd(u<<1|1,m+1,r,x,y,k);
tr[u]=tr[u<<1]+tr[u<<1|1];
}
int get(int u,int l,int r,int x,int y) {
push(u,l,r);
if (x>r||y<l) return 0;
if (l>=x&&r<=y) {
return tr[u];
}
int m=l+r>>1;
int q1=get(u<<1,l,m,x,y);
int q2=get(u<<1|1,m+1,r,x,y);
return q1+q2;
}
int at(int pos) {
return get(1,0,n,pos,pos);
}
};
int a[N];
void levi() {
int n,q,s,t;
cin>>n>>q>>s>>t;
Segtree se;
se.init(n);
for (int i=1;i<=n+1;++i) {
cin>>a[i-1];
se.upd(1,0,n,i-1,i-1,a[i-1]);
}
int res=0;
for (int i=1;i<=n;++i) {
int diff=abs(a[i]-a[i-1]);
if (a[i-1]<a[i]) res-=s*diff;
else res+=t*diff;
}
cout<<res<<'\n';
for (int i=1;i<=q;++i) {
int l,r,x;
cin>>l>>r>>x;
int diff=se.at(l-1)-se.at(l);
int fa=(diff<0)?s*abs(diff):-t*abs(diff),re=0;
if (r!=n) {
int diff2=(se.at(r)-se.at(r+1));
re=(diff2<0)?s*abs(diff2):-t*abs(diff2);
}
se.upd(1,0,n,l,r,x);
res+=re+fa;
diff=se.at(l-1)-se.at(l);
if (diff<0) res-=s*abs(diff);
else res+=t*diff;
if (r!=n) {
diff=se.at(r)-se.at(r+1);
if(diff<0){
res-=s*abs(diff);
}
else res+=t*diff;
}
cout<<res<<'\n';
}
}
int32_t main() {
ios_base::sync_with_stdio(0);
cin.tie(0);int tt=1;//cin>>tt;
while(tt--)levi();
}
