#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#define pb push_back
#define ff first
#define ss second
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define int long long
#define double long double
#define order_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
///* __ __ __ */
///* ====== _ /| /| __ _ / | | /| | @ | | | | / /| |\ | / | | @ | / */
///* \- || |_| |_ / |/ | | | |_ |- | |--| /-| | | \ \ |==| |- /=| | \ | | |--| | |- */
///* || | | |_ / | |__| _| |_ \__ | | / | |__ | __| | | | \ / | | \| \__ | | | | \ */
///*
typedef vector<int> vi;
typedef vector<double> vd;
typedef pair<int,int> pii;
typedef vector<pii> vii;
typedef vector<vi> vv;
const int N = 2e5+4, inf = 1e8;
int a[N];
int b[N*3]{};
void push(int i, int l, int r){
if(l == r){
a[l] += b[i];
b[i] = 0;
return;
}
b[i*2] += b[i];
b[i*2+1] += b[i];
b[i]=0;
}
void upd(int i, int l, int r, int tl, int tr, int sum){
push(i, l, r);
if(l > tr || r < tl || r < l)return;
if(tl <= l && r <= tr){
b[i] += sum;
return;
}
int m = (l+r)>>1;
upd(i*2, l, m, tl, tr, sum);
upd(i*2+1, m+1, r, tl, tr, sum);
}
void get(int i, int l, int r, int pos){
if(pos==0)return;
push(i, l, r);
if(l == r && l == pos)return;
int m = (l+r)>>1;
if(pos <= m)get(i*2, l, m, pos);
else get(i*2+1, m+1, r, pos);
}
void solve(){
int n, q, s, t;
cin >> n >> q >> s >> t;
for(int i = 0; i <= n; i++){
cin >> a[i];
}
int ans = 0;
for(int i = 1; i <= n; i++){
int df = a[i-1]-a[i];
if(df > 0)ans += df*t;
else ans += df*s;
}
while(q--){
int l, r, x;
cin >> l >> r >> x;
get(1, 1, n, l);
get(1, 1, n, l-1);
int df = a[l-1]-a[l];
if(df > 0)ans -= df*t;
else ans -= df*s;
if(r < n){
get(1, 1, n, r);
get(1, 1, n, r+1);
int df = a[r]-a[r+1];
if(df > 0)ans -= df*t;
else ans -= df*s;
}
upd(1, 1, n, l, r, x);
get(1, 1, n, l);
get(1, 1, n, l-1);
int nwd = a[l-1] - a[l];
if(nwd > 0)ans += nwd*t;
else ans += nwd*s;
if(r < n){
get(1, 1, n, r);
get(1, 1, n, r+1);
int nwd = a[r] - a[r+1];
if(nwd > 0)ans += nwd*t;
else ans += nwd*s;
}
cout << ans << '\n';
}
}
main(){
ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
int test = 1;
//~ cin >> test;
while(test--){
solve();
}
}
