#include <bits/stdc++.h>
#define int long long
using namespace std;
const int MAXN = (int)2e5 + 5;
int a[MAXN];
int tree[MAXN * 4], lazy[MAXN * 4];
int n, q, s, t;
void build(int v, int tl, int tr) {
if (tl == tr) {
tree[v] = a[tl];
return;
}
int mid = (tl + tr) >> 1;
build(v + v, tl, mid);
build(v + v + 1, mid + 1, tr);
}
void push(int v, int tl, int tr) {
if (!lazy[v]) {
return;
}
if (tl != tr) {
lazy[v + v] += lazy[v];
lazy[v + v + 1] += lazy[v];
} else {
tree[v] += lazy[v];
}
lazy[v] = 0;
}
void upd(int l, int r, int val, int v, int tl, int tr) {
push(v, tl, tr);
if (l <= tl && tr <= r) {
lazy[v] = val;
push(v, tl, tr);
return;
}
if (l > tr || tl > r) {
return;
}
int mid = (tl + tr) >> 1;
upd(l, r, val, v + v, tl, mid);
upd(l, r, val, v + v + 1, mid + 1, tr);
}
int get(int pos, int v, int tl, int tr) {
if (pos == 0) { // case
return 0;
}
push(v, tl, tr);
if (tl == tr) {
return tree[v];
}
int mid = (tl + tr) >> 1;
if (pos <= mid) {
return get(pos, v + v, tl, mid);
} else {
return get(pos, v + v + 1, mid + 1, tr);
}
}
int calc(int i, int j) { // i < j
int x = get(i, 1, 1, n);
int y = get(j, 1, 1, n);
int diff = abs(x - y);
if (x < y) {
return -(diff * s);
} else {
return diff * t;
}
}
signed main() {
cin >> n >> q >> s >> t;
for (int i = 0; i <= n; i++) {
scanf("%lld", &a[i]);
}
build(1, 1, n);
int ans = 0;
for (int i = 0; i < n; i++) {
ans += calc(i, i + 1);
}
while (q--) {
int l, r, val;
scanf("%lld %lld %lld", &l, &r, &val);
if (l - 1 >= 0) {
ans -= calc(l - 1, l);
}
if (r + 1 <= n) {
ans -= calc(r, r + 1);
}
upd(l, r, val, 1, 1, n);
if (l - 1 >= 0) {
ans += calc(l - 1, l);
}
if (r + 1 <= n) {
ans += calc(r, r + 1);
}
printf("%lld\n", ans);
}
}
