#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define endl '\n'
#define INF 1e9+7
#define all(x) x.begin(),x.end()
using namespace std;
using namespace __gnu_pbds;
using ll=long long;
using pii=pair<int,int>;
using ppi=pair<int,pii>;
using oset=tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update>;
template<typename T>
void _print(vector<T> x) {cerr<<"{"; for(auto e:x) cerr<<e<<","; cerr<<"}";}
void _print(pii x) {cerr<<"{"<<x.first<<","<<x.second<<"}";}
template<typename T>
void _print(T x) {cerr<<x;}
void dbg() {cerr<<endl;}
template<typename Head,typename... Tail>
void dbg(Head H,Tail... T) {
_print(H);
if(sizeof...(T)) cerr<<",";
else cerr<<"\"]";
dbg(T...);
}
#define debug(...) cerr<<"["<<#__VA_ARGS__<<"]:[\"",dbg(__VA_ARGS__)
//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int mxn=2e5+10;
ll n,m,S,T;
vector<ll> a;
ll t[3*mxn];
bool flag[3*mxn];
void build(int v,int tl,int tr) {
if(tl==tr) t[v]=a[tl];
else {
int mid=(tl+tr)/2;
build(2*v,tl,mid);
build(2*v+1,mid+1,tr);
}
}
void add(int v,int tl,int tr,int l,int r,int val) {
if(tl>tr or tl>r or tr<l) return;
if(tl>=l and tr<=r) t[v]+=val;
else {
int mid=(tl+tr)/2;
add(2*v,tl,mid,l,r,val);
add(2*v+1,mid+1,tr,l,r,val);
}
}
ll get(int v,int tl,int tr,int idx) {
if(tl==tr) return t[v];
int mid=(tl+tr)/2;
if(idx<=mid) return t[v]+get(2*v,tl,mid,idx);
else return t[v]+get(2*v+1,mid+1,tr,idx);
}
void print() {
for(int i=0;i<n;i++) {
cout<<get(1,0,n-1,i)<<" ";
}
cout<<endl;
}
ll f(ll u,ll v) {
if(u<v) return -1LL*S*(v-u);
return 1LL*T*(u-v);
}
int main () {
ios::sync_with_stdio(false); cin.tie(0);
cin>>n>>m>>S>>T; n++;
a.resize(n);
for(int i=0;i<n;i++) cin>>a[i];
build(1,0,n-1);
ll ans=0;
for(int i=1;i<n;i++) {
ans+=f(a[i-1],a[i]);
}
// debug(ans);
for(int i=0;i<m;i++) {
ll l,r,x; cin>>l>>r>>x;
if(l-1>=0) {
ll a1=get(1,0,n-1,l-1);
ll a2=get(1,0,n-1,l);
// debug(a1,a2,f(a1,a2));
ans-=f(a1,a2);
ans+=f(a1,a2+x);
}
if(r+1<n) {
ll a1=get(1,0,n-1,r);
ll a2=get(1,0,n-1,r+1);
ans-=f(a1,a2);
ans+=f(a1+x,a2);
}
add(1,0,n-1,l,r,x);
cout<<ans<<endl;
}
}
