#include<bits/stdc++.h>
#define int long long
using namespace std;
int n, q, s, t;
vector<int> a, tr, tr_bocil, bocil;
void build(int pos=0, int l=0, int r=n) {
if(l==r) {tr_bocil[pos]=bocil[l]; tr[pos]=a[r]; return;}
int mid=l+r>>1;
build(2*pos+1, l, mid);
build(2*pos+2, mid+1, r);
}
void push(int pos) {
tr_bocil[2*pos+1]+=tr_bocil[pos];
tr_bocil[2*pos+2]+=tr_bocil[pos];
tr_bocil[pos]=0;
tr[2*pos+1]+=tr[pos];
tr[2*pos+2]+=tr[pos];
tr[pos]=0;
}
int get_bocil(int idx, int pos=0, int l=0, int r=n) {
if(l==r) return tr_bocil[pos];
push(pos); int mid=l+r>>1;
if(idx<=mid) return get_bocil(idx, 2*pos+1, l, mid);
return get_bocil(idx, 2*pos+2, mid+1, r);
}
void update_bocil(int inc, int ll, int rr, int pos=0, int l=0, int r=n) {
if(ll>rr || l>rr || ll>r) return;
if(ll==l && rr==r) {tr_bocil[pos]+=inc; return;}
push(pos); int mid=l+r>>1;
update_bocil(inc, ll, min(rr, mid), 2*pos+1, l, mid);
update_bocil(inc, max(mid+1, ll), rr, 2*pos+2, mid+1, r);
}
int get(int idx, int pos=0, int l=0, int r=n) {
if(l==r) return tr[pos];
push(pos); int mid=l+r>>1;
if(idx<=mid) return get(idx, 2*pos+1, l, mid);
return get(idx, 2*pos+2, mid+1, r);
}
void update(int inc, int ll, int rr, int pos=0, int l=0, int r=n) {
if(ll>rr || l>rr || ll>r) return;
if(ll==l && rr==r) {tr[pos]+=inc; return;}
push(pos); int mid=l+r>>1;
update(inc, ll, min(rr, mid), 2*pos+1, l, mid);
update(inc, max(mid+1, ll), rr, 2*pos+2, mid+1, r);
}
signed main() {
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n >> q >> s >> t;
a.resize(n+1); bocil.resize(n+1);
tr_bocil.resize(n+1 << 2); tr.resize(n+1 << 2);
for(int &p : a) cin >> p;
for(int i=1; i<=n; i++) {
if(a[i-1]<a[i]) bocil[i]=bocil[i-1]-s*(a[i]-a[i-1]);
else bocil[i]=bocil[i-1]+t*(a[i-1]-a[i]);}
build();
while(q--) {
int l, r, x; cin >> l >> r >> x;
int l_bef=get_bocil(l);
int B=get(l-1), A=get(l)+x;
int now; if(B<A) now=get_bocil(l-1)-s*(A-B);
else now=get_bocil(l-1)+t*(B-A);
update_bocil(now-l_bef, l, r);
update(x, l, r);
if(r<n) {
l_bef=get_bocil(r+1);
B=get(r); A=get(r+1);
if(B<A) now=get_bocil(r)-s*(A-B);
else now=get_bocil(r)+t*(B-A);
update_bocil(now-l_bef, r+1, n);
}
cout << get_bocil(n) << '\n';
}
return 0;
}
