#include <bits/stdc++.h>
#define ll long long
#define mp make_pair
#define pb push_back
using namespace std;
const int maxn = 200100;
ll n, q, s, t;
ll a[maxn];
ll tree[4*maxn];
ll lazy[4*maxn];
void push_update(int li, int ri, int index) {
if(lazy[index] != 0) {
tree[index] += lazy[index];
if(li != ri) {
lazy[2*index] += lazy[index];
lazy[2*index+1] += lazy[index];
}
lazy[index] = 0;
}
}
void build(int li=0, int ri=n, int index=1) {
if(li == ri) {
tree[index] = a[li];
}
else {
int mid = (li + ri) / 2;
build(li, mid, 2*index);
build(mid+1, ri, 2*index+1);
}
}
void update(int ul, int ur, ll uval, int li=0, int ri=n, int index=1) {
push_update(li, ri, index);
if(li > ur || ri < ul) return;
else if(li >= ul && ri <= ur) {
lazy[index] += uval;
push_update(li, ri, index);
}
else {
int mid = (li + ri) / 2;
update(ul,ur,uval,li,mid,2*index);
update(ul,ur,uval,mid+1,ri,2*index+1);
tree[index] = max(tree[2*index], tree[2*index+1]);
}
}
ll query(int qind, int li=0, int ri=n, int index=1) {
push_update(li, ri, index);
if(li == ri) return tree[index];
else {
int mid = (li + ri) / 2;
ll x;
if(qind <= mid) x = query(qind, li, mid, 2*index);
else x = query(qind, mid+1, ri, 2*index+1);
tree[index] = max(tree[2*index], tree[2*index+1]);
return x;
}
}
ll f(int i) {
if(i == n) return 0LL;
ll in = query(i+1);
ll ic = query(i);
ll diff = abs(in - ic);
if(ic < in) return -diff * s;
else return diff*t;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cin>>n>>q>>s>>t;
for(int i=0;i<=n;i++) {
cin>>a[i];
}
build();
ll result = 0LL;
for(int i=0;i<=n;i++) {
result += f(i);
}
ll l, r, v;
while(q--) {
cin>>l>>r>>v;
result -= f(l-1);
result -= f(r);
update(l, r, v);
result += f(l-1);
result += f(r);
cout<<result<<"\n";
}
return 0;
}
