#include <bits/stdc++.h>
using namespace std;
// Tazhibaev Iskhak
// call me, if scholarship $$ is at least ELON_MUSK_MAX
#define int long long
#define ff first
#define ss second
#define all(a) a.begin(), a.end()
const int mod = 1e9 + 7;
const int N = 2e5;
int n, q, S, T;
int lazy[4*N], t[4*N];
int a[N+10];
void push(int v, int vl, int vr){
if(!lazy[v]) return;
t[v]+= (lazy[v] * (vr-vl+1));
if(vl != vr){
lazy[v<<1]+= lazy[v];
lazy[v<<1|1]+= lazy[v];
}
lazy[v] = 0;
}
void add(int l, int r, int x, int v, int vl, int vr){
push(v, vl, vr);
if(l > vr or vl > r) return;
if(l <= vl && r >= vr){
lazy[v]+= x;
push(v, vl, vr);
return;
}
int mid = (vl + vr)>>1;
add(l, r, x, v<<1, vl, mid);
add(l, r, x, v<<1|1, mid+1, vr);
}
int get(int pos, int v, int vl, int vr){
push(v, vl, vr);
if(vl == vr) return t[v];
int mid = (vl + vr)>>1;
if(mid >= pos) return get(pos, v<<1, vl, mid);
else return get(pos, v<<1|1, mid+1, vr);
}
int sum;
void inv_degree(int idx){
int A;
int B = get(idx, 1, 1, n);
if(idx == 1) A = 0;
else A = get(idx-1, 1, 1, n);
if(B > A){
sum+= S * abs(B-A);
}else{
sum-= T * abs(B-A);
}
}
void degree(int idx){
int A;
int B = get(idx, 1, 1, n);
if(idx == 1) A = 0;
else A = get(idx-1, 1, 1, n);
if(B > A){
sum-= S * abs(B-A);
}else{
sum+= T * abs(B-A);
}
}
signed main(){
ios::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
cin >> n >> q >> S >> T;
for(int i = 0;i <= n; i++){
cin >> a[i];
add(i, i, a[i], 1, 1, n);
}
for(int i = 1;i <= n; i++){
degree(i);
}
while(q--){
int l, r, x; cin >> l >> r >> x;
if(r + 1 <= n) inv_degree(r+1);
inv_degree(l);
add(l, r, x, 1, 1, n);
if(r+1 <= n){
degree(r+1);
}
degree(l);
cout << sum << '\n';
}
return 0;
}
