#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
int N, Q;
ll S, T, A[200001];
ll t[1000000];
void build(int v, int tl, int tr)
{
if (tl == tr)
{
t[v] = A[tl];
return;
}
int tm = (tl + tr) / 2;
build(v * 2, tl, tm);
build(v * 2 + 1, tm + 1, tr);
t[v] = 0;
}
void add(int v, int tl, int tr, int l, int r, ll val)
{
if (r < tl || tr < l)
return;
if (l <= tl && tr <= r)
{
t[v] += val;
return;
}
int tm = (tl + tr) / 2;
add(v * 2, tl, tm, l, r, val);
add(v * 2 + 1, tm + 1, tr, l, r, val);
}
ll query(int v, int tl, int tr, int idx)
{
if (tl == tr)
return t[v];
int tm = (tl + tr) / 2;
if (idx <= tm)
return t[v] + query(v * 2, tl, tm, idx);
else
return t[v] + query(v * 2 + 1, tm + 1, tr, idx);
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> N >> Q >> S >> T;
for (int i = 0; i <= N; i++)
cin >> A[i];
build(1, 0, N);
ll res = 0;
for (int i = 0; i < N; i++)
res += max(0LL, A[i] - A[i + 1]) * T - max(0LL, A[i + 1] - A[i]) * S;
int L, R;
ll x;
while (Q--)
{
cin >> L >> R >> x;
A[L - 1] = query(1, 0, N, L - 1);
A[R + 1] = query(1, 0, N, R + 1);
A[L] = query(1, 0, N, L);
A[R] = query(1, 0, N, R);
A[N+1] = A[N];
res -= T * max(0LL, A[L - 1] - A[L]) - S * max(0LL, A[L] - A[L - 1]);
res -= T * max(0LL, A[R] - A[R + 1]) - S * max(0LL, A[R + 1] - A[R]);
add(1, 0, N, L, R, x);
A[L] = query(1, 0, N, L);
A[R] = query(1, 0, N, R);
A[N+1] = A[N];
res += T * max(0LL, A[L - 1] - A[L]) - S * max(0LL, A[L] - A[L - 1]);
res += T * max(0LL, A[R] - A[R + 1]) - S * max(0LL, A[R + 1] - A[R]);
cout << res << '\n';
}
return 0;
}
