#include <iostream>
#include <map>
using namespace std;
int N;
int* A;
map<int, int> M;
int g(int p1, int p2)
{
return (N+1)*p1 + p2;
}
void build(int p1, int p2)
{
if(p1 == p2) M[g(p1, p2)] = A[p1];
else
{
build(p1, (p1+p2)/2);
build((p1+p2)/2 + 1, p2);
M[g(p1, p2)] = 0;
}
}
int E(int p1, int p2, int p)
{
if(p1 == p2) return M[g(p1, p2)];
if(p <= (p1+p2)/2) return M[g(p1, p2)] + E(p1, (p1+p2)/2, p);
else return M[g(p1, p2)] + E((p1+p2)/2 + 1, p2, p);
}
int F(int p)
{
if(p == 0) return 0;
return E(1, N, p);
}
void update(int p1, int p2, int a1, int a2, int u) //map range, update range, update value
{
if(a2 < p1 || p2 < a1) return;
if(a1 <= p1 && p2 <= a2)
{
M[g(p1, p2)] += u;
return;
}
update(p1, (p1+p2)/2, a1, a2, u);
update((p1+p2)/2 + 1, p2, a1, a2, u);
}
int main()
{
int Q, S, T;
cin >> N >> Q >> S >> T;
A = new int[N+1];
for(int i = 0; i <= N; i++) cin >> A[i];
build(1, N);
int w = 0;
for(int i = 1; i <= N; i++) w += (A[i-1]-A[i]) * ((A[i]>A[i-1])?S:T);
int l, r, u;
int L1, L2, R1, R2;
for(int i = 1; i <= Q; i++)
{
cin >> l >> r >> u;
L1 = F(l-1);
L2 = F(l);
if(r != N)
{
R1 = F(r);
R2 = F(r+1);
}
w -= (L1-L2) * ((L2>L1)?S:T);
if(r != N) w -= (R1-R2) * ((R2>R1)?S:T);
update(1, N, l, r, u);
L1 = F(l-1);
L2 = F(l);
if(r != N)
{
R1 = F(r);
R2 = F(r+1);
}
w += (L1-L2) * ((L2>L1)?S:T);
if(r != N) w += (R1-R2) * ((R2>R1)?S:T);
cout << w << '\n';
}
return 0;
}
