#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pb push_back
const int maxN = 2e5 + 7;
int a[maxN];
int n, q, s, T;
int t[maxN * 4], lz[maxN * 4];
void build(int v, int tl, int tr) {
if(tl == tr) {
t[v] = a[tl];
} else {
int tm = (tl + tr) / 2;
build(v * 2, tl, tm);
build(v * 2 + 1, tm + 1, tr);
t[v] = t[v * 2] + t[v * 2 + 1];
}
}
void push(int v, int tl, int tr) {
if(!lz[v]) return;
t[v] += (tr - tl + 1) * lz[v];
if(tl != tr) {
lz[v * 2] += lz[v];
lz[v * 2 + 1] += lz[v];
} else {
a[tl] += lz[v];
}
lz[v] = 0;
}
int get(int v, int tl, int tr, int idx) {
push(v, tl, tr);
if(tl == tr) return t[v];
int tm = (tl + tr) / 2;
if(idx <= tm) return get(v * 2, tl, tm, idx);
return get(v * 2 + 1, tm + 1, tr, idx);
}
void upd(int v, int tl, int tr, int l, int r, int val) {
push(v, tl, tr);
if(l > tr || r < tl) return;
if(l <= tl && tr <= r) {
lz[v] += val;
push(v, tl, tr);
return;
}
int tm = (tl + tr) / 2;
upd(v * 2, tl, tm, l, r, val);
upd(v * 2 + 1, tm + 1, tr, l, r, val);
t[v] = t[v * 2] + t[v * 2 + 1];
}
int get(int d) {
if(d > 0) return -d * s;
return -d * T;
}
void solve() {
cin >> n >> q >> s >> T;
for(int i = 0; i <= n; i++) {
cin >> a[i];
}
build(1, 1, n);
int ans = 0;
for(int i = 0; i < n; i++) {
int val = a[i + 1] - a[i];
ans += get(val);
}
while(q--) {
int l, r, x;
cin >> l >> r >> x;
get(1, 1, n, l - 1);
get(1, 1, n, r + 1);
get(1, 1, n, l);
get(1, 1, n, r);
int val = a[l] - a[l - 1];
ans -= get(val);
if(r < n) {
val = a[r + 1] - a[r];
ans -= get(val);
}
upd(1, 1, n, l, r, x);
get(1, 1, n, l - 1);
get(1, 1, n, r + 1);
get(1, 1, n, l);
get(1, 1, n, r);
val = a[l] - a[l - 1];
ans += get(val);
if(r < n) {
val = a[r + 1] - a[r];
ans += get(val);
}
cout << ans << '\n';
}
}
signed main() {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
//freopen("input.txt", "r", stdin);
int t = 1;
//cin >> t;
while(t--) solve();
}
