//IN THE NAME OF GOD
#include<bits/stdc++.h>
#pragma GCC optimize("O2,unroll-loops")
#define endl '\n'
#define F first
#define S second
using namespace std;
typedef long long ll;
const ll N = 2e5+7;
ll a[N], seg[N<<2];
void build(ll ind, ll l, ll r){
if (l == r){
seg[ind] = a[l];
return;
}
ll mid = (l+r)>>1;
build(2*ind,l,mid);
build(2*ind+1,mid+1,r);
}
void shift(ll ind, ll l, ll r){
if (l == r) return;
seg[2*ind] += seg[ind];
seg[2*ind+1] += seg[ind];
seg[ind] = 0;
}
void upd(ll ind, ll l, ll r, ll st, ll en, ll val){
shift(ind,l,r);
if (l > en || st > r) return;
if (l == r || (l >= st && r <= en)){
seg[ind] += val;
return;
}
ll mid = (l+r)>>1;
upd(2*ind,l,mid,st,en,val);
upd(2*ind+1,mid+1,r,st,en,val);
}
ll get(ll ind, ll l, ll r, ll id){
shift(ind,l,r);
if (l == r) return seg[ind];
ll mid = (l+r)>>1;
if (id <= mid) return get(2*ind,l,mid,id);
else return get(2*ind+1,mid+1,r,id);
}
int32_t main(){
ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
ll n,q,s,t; cin >> n >> q >> s >> t;
for(ll i=0; i<=n; i++) cin >> a[i];
build(1,0,n);
ll mos = 0, man = 0;
for(ll i=1; i<=n; i++){
if (a[i] > a[i-1]) man += (a[i] - a[i-1]);
else mos += (a[i-1] - a[i]);
}
while(q--){
ll l,r,x; cin >> l >> r >> x;
if (l > 0){
ll a = get(1,0,n,l-1), b = get(1,0,n,l);
if (a < b) man -= (b-a);
else mos -= (a-b);
b += x;
if (a < b) man += (b-a);
else mos += (a-b);
}
if (r < n){
ll a = get(1,0,n,r), b = get(1,0,n,r+1);
if (a < b) man -= (b-a);
else mos -= (a-b);
a += x;
if (a < b) man += (b-a);
else mos += (a-b);
}
upd(1,0,n,l,r,x);
ll ans = mos * t - man * s;
cout << ans << endl;
}
return 0;
}
