#include <bits/stdc++.h>
#define ll long long
#define pii pair<int,int>
#define pll pair<ll,ll>
#define vi vector<int>
#define vl vector<ll>
#define mp make_pair
#define pb push_back
using namespace std;
int n, q, s, t;
vi arr;
class klas{
public:
ll l;
ll r;
ll temp;
};
vector<klas> tree(4 * 200000);
ll lazy[4 * 200000];
void build(int node, int l, int r){
if(l == r){
//cout<<l<<endl;
if(l == n + 1) return;
klas cur;
cur.l = arr[l];
cur.r = arr[l];
cur.temp = 0;
tree[node] = cur;
}
else{
int mid = (l + r) / 2;
build(node * 2, l, mid);
build(node * 2 + 1, mid + 1, r);
klas next;
next.l = tree[node * 2].l;
next.r = tree[node * 2 + 1].r;
next.temp =tree[node * 2].temp + tree[node * 2 + 1].temp;
if(tree[node * 2].r < tree[node * 2 + 1].l){
ll diff = tree[node * 2 + 1].l - tree[node * 2].r;
next.temp= next.temp - diff * s;
//cout<<tree[node * 2 + 1].l <<" "<<tree[node * 2].r<<endl;
}
else if(tree[node * 2].r > tree[node * 2 + 1].l){
ll diff = tree[node * 2].r - tree[node * 2 + 1].l;
next.temp = next.temp + diff * t;
//cout<<tree[node * 2 + 1].l <<" "<<tree[node * 2].r<<endl;
}
tree[node] = next;
}
}
/*void update(int node, int l, int r, int pos, int x){
if(l == r && l == pos)
{
tree[node].l += x;
tree[node].r += x;
}
else{
int mid = (l + r) / 2;
if(pos <= mid)
update(node * 2, l, mid, pos, x);
else
update(node * 2 + 1, mid + 1, r, pos, x);
klas next;
next.l = tree[node * 2].l;
next.r = tree[node * 2 + 1].r;
next.temp =tree[node * 2].temp + tree[node * 2 + 1].temp;
if(tree[node * 2].r < tree[node * 2 + 1].l){
int diff = tree[node * 2 + 1].l - tree[node * 2].r;
next.temp= next.temp - diff * s;
//cout<<tree[node * 2 + 1].l <<" "<<tree[node * 2].r<<endl;
}
else if(tree[node * 2].r > tree[node * 2 + 1].l){
int diff = tree[node * 2].r - tree[node * 2 + 1].l;
next.temp = next.temp + diff * t;
//cout<<tree[node * 2 + 1].l <<" "<<tree[node * 2].r<<endl;
}
tree[node] = next;
}
}*/
void update(int node, int l, int r, int L, int R, int x){
if(lazy[node] != 0){
tree[node].l += lazy[node];
tree[node].r += lazy[node];
if(l != r){
lazy[node * 2] += lazy[node];
lazy[node * 2 + 1] += lazy[node];
}
lazy[node] = 0;
}
if(r < L || R < l) return;
if(L <= l && r <= R){
tree[node].l += x;
tree[node].r += x;
if(l != r){
lazy[node * 2] += x;
lazy[node * 2 + 1] += x;
}
return;
}
int mid = (l + r) / 2;
update(node * 2, l, mid, L, R, x);
update(node * 2 + 1, mid + 1, r, L, R, x);
klas next;
next.l = tree[node * 2].l;
next.r = tree[node * 2 + 1].r;
next.temp = tree[node * 2].temp + tree[node * 2 + 1].temp;
if(tree[node * 2].r < tree[node * 2 + 1].l){
ll diff = tree[node * 2 + 1].l - tree[node * 2].r;
next.temp= next.temp - diff * s;
//cout<<diff<<" "<<tree[node * 2].r<<" "<<tree[node * 2 + 1].l<<endl;
//cout<<tree[node * 2 + 1].l <<" "<<tree[node * 2].r<<endl;
}
else if(tree[node * 2].r > tree[node * 2 + 1].l){
ll diff = tree[node * 2].r - tree[node * 2 + 1].l;
next.temp = next.temp + diff * t;
//cout<<diff<<" "<<tree[node * 2].r<<" "<<tree[node * 2 + 1].l<<endl;
//cout<<tree[node * 2 + 1].l <<" "<<tree[node * 2].r<<endl;
}
tree[node] = next;
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
memset(lazy, 0, sizeof(lazy));
cin>>n>>q>>s>>t;
for(int i = 0; i <=n; i++){
int a;
cin>>a;
arr.pb(a);
}
build(1, 0, n);
//cout<<tree[1].temp<<endl;
while(q--){
int a, b, x;
cin>>a>>b>>x;
update(1, 0, n, a, b, x);
cout<<tree[1].temp<<endl;
}
}
