#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
using ll = long long;
struct node {
ll val = 0;
bool pd = false;
ll lz = 0;
};
struct stree {
#define lc v*2
#define rc v*2+1
vector <node> tree;
stree (int s) {
tree.resize(s * 4);
}
void pushdown(int v) {
if (!tree[v].pd)
return;
tree[v].pd = false;
tree[lc].pd = tree[rc].pd = true;
tree[lc].lz += tree[v].lz;
tree[rc].lz += tree[v].lz;
tree[v].lz = 0;
}
void update(int v, int tl, int tr, int l, int r, ll delta) {
if (tl > r || tr < l)
return;
if (tl >= l && tr <= r) {
tree[v].lz += delta;
tree[v].pd = true;
return;
}
pushdown(v);
int tm = (tl + tr) / 2;
update(lc, tl, tm, l, r, delta);
update(rc, tm+1, tr, l, r, delta);
}
ll query(int v, int tl, int tr, int p) {
if (tl == tr)
return tree[v].lz + tree[v].val;
pushdown(v);
int tm = (tl + tr) / 2;
if (tm >= p && tl <= p)
return query(lc, tl, tm, p);
else
return query(rc, tm+1, tr, p);
}
};
int main() {
int N, Q;
ll S, T;
cin >> N >> Q >> S >> T;
vector <ll> a(N+1);
for (int i = 0; i <= N; i++)
cin >> a[i];
stree tree(N+3);
int sz = N+2;
for (int i = 0; i <= N; i++)
tree.update(1, 0, sz, i, i, a[i]);
ll ans = 0;
for (int i = 0; i+1 <= N; i++) {
if (a[i] < a[i+1])
ans -= S * (a[i+1] - a[i]);
else
ans += T * (a[i] - a[i+1]);
}
while (Q--) {
int l, r, x;
cin >> l >> r >> x;
ll a = tree.query(1, 0, sz, l-1);
ll b = tree.query(1, 0, sz, l);
ll c = tree.query(1, 0, sz, r);
ll d = tree.query(1, 0, sz, r+1);
if (a < b)
ans += S * (b - a);
else
ans -= T * (a - b);
if (r+1 <= N) {
if (c < d)
ans += S * (d - c);
else
ans -= T * (c - d);
}
b += x;
c += x;
if (a < b)
ans -= S * (b - a);
else
ans += T * (a - b);
if (r+1 <= N) {
if (c < d)
ans -= S * (d - c);
else
ans += T * (c - d);
}
tree.update(1, 0, sz, l, r, x);
cout << ans << '\n';
}
}
