#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("Ofast,fast-math,O3")
#define pb push_back
#define ll long long
#define f first
#define s second
#define int long long
//#define sz(v) int(v.size())
#define all(v) v.begin(),v.end()
int mod = 1e9 + 7;
const int N = 2e5 + 2,k = 317 + 1;
const int inf = 2e9;
int d[N * 4],tr[N * 4],a[N];
int n,q,s,t,ans;
int func(int x,int y){
if(x < y) return (x - y) * s;
else return (x - y) * t;
}
void build(int u,int l,int r){
if(l == r){
tr[u] = a[l];
return;
}
int mid = (l + r) / 2;
build(u * 2,l,mid),build(u * 2 + 1,mid + 1,r);
}
void push(int u,int l,int r){
int mid = (l + r) / 2;
tr[u] += d[u];
if(l != r)d[u * 2] += d[u],d[u * 2 + 1] += d[u];
d[u] = 0;
}
void upd(int u,int l,int r,int lx,int rx,int x){
push(u,l,r);
if(l >= lx && r <= rx){
d[u] += x;
push(u,l,r);
return;
}
else if(l > rx || r < lx) return;
int mid = (l + r) / 2;
upd(u * 2,l,mid,lx,rx,x);
upd(u * 2 + 1,mid + 1,r,lx,rx,x);
}
int get(int u,int l,int r,int lx,int rx){
push(u,l,r);
if(l >= lx && r <= rx) return tr[u];
else if(l > rx || r < lx) return 0;
int mid = (l + r) / 2;
return get(u * 2,l,mid,lx,rx) + get(u * 2 + 1,mid + 1,r,lx,rx);
}
void solve(){
cin >> n >> q >> s >> t;
for(int i = 0; i <= n; i++){
cin >> a[i];
}
for(int i = 1; i <= n; i++){
ans += func(a[i - 1],a[i]);
}
build(1,0,n);
while(q--){
int l,r,x;
cin >> l >> r >> x;
upd(1,0,n,l,r,x);
if(l != 0)ans -= func(a[l - 1],a[l]);
if(r != n) ans -= func(a[r],a[r + 1]);
a[r] = get(1,0,n,r,r);
a[l] = get(1,0,n,l,l);
if(l != 0){
a[l - 1] = get(1,0,n,l - 1,l - 1);
ans += func(a[l - 1],a[l]);
}
if(r != n){
a[r + 1] = get(1,0,n,r + 1,r + 1);
ans += func(a[r],a[r + 1]);
}
cout << ans << '\n';
}
}
signed main(){
//freopen("time.in", "r", stdin);
//freopen("time.out", "w", stdout);
ios_base::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
int t = 1;
while(t--){
solve();
}
}
