#include<bits/stdc++.h>
using namespace std;
bool M1;
#define PI 3.14159265358979323846
#define sz(a) (int)a.size()
#define all(x) x.begin(),x.end()
#define ii pair<long long,int>
#define iii pair<int,ii>
#define iv pair<ii,ii>
#define se second
#define fi first
#define ffi fi.fi
#define sfi se.fi
#define sse se.se
#define fse fi.se
#define lt(i, c, d) for(int i = c; i <= d; ++i)
#define fl(i, c, d) for(int i = d; i >= c; --i)
#define pb push_back
// #define int long long
#define emb emplace_back
#define emf emplace_front
#define em emplace
#define look_memory cerr<<abs(&M2-&M1)/1024.0/1024<<'\n'
#define look_time cerr << "TIME : " << clock() * 0.001 << "s" <<'\n'
const int N=1e6+5,lg=30,mod=1e9+7;
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());
int Rand(int u,int v){
return u+rd()%(v-u+1);
}
int dx[]={1,0,-1,0,1,1,-1,-1};
int dy[]={0,-1,0,1,1,-1,1,-1};
int node,query,s,t,a[N];
struct segmax {
int n;
vector<int> st, lazy;
segmax() {};
segmax(int _n): n(_n), st(n * 4 + 5, 0), lazy(n * 4 + 5, 0) {};
void build(int id, int l, int r) {
if (l == r) {
st[id] = a[l];
return;
}
int mid = (l + r) >> 1;
build(id << 1, l, mid);
build(id << 1 | 1, mid + 1, r);
st[id] = max(st[id << 1], st[id << 1 | 1]);
}
void down(int id) {
if (lazy[id] == 0) return;
lazy[id << 1] += lazy[id];
lazy[id << 1 | 1] += lazy[id];
st[id << 1] += lazy[id];
st[id << 1 | 1] += lazy[id];
lazy[id] = 0;
}
void update(int id, int l, int r, int u, int v, int val) {
if (r < u || l > v) return;
if (l >= u && r <= v) {
st[id] += val;
lazy[id] += val;
return;
}
down(id);
int mid = (l + r) >> 1;
update(id << 1, l, mid, u, v, val);
update(id << 1 | 1, mid + 1, r, u, v, val);
}
int get(int id, int l, int r, int i) {
if (r==l) return st[id];
down(id);
int mid = (l + r) >> 1;
if(i<=mid)
return get(id << 1, l, mid, i);
return get(id << 1 | 1, mid + 1, r, i);
}
};
long long ans;
bool M2;
void solve(){
cin >> node>> query >> s >>t;
segmax seg(node);
for(int i=0;i<=node;++i){
cin >> a[i];
}
seg.build(1,0,node);
int up=0,down=0;
for(int i=1;i<=node;++i){
if(a[i]>a[i-1])up+=a[i]-a[i-1];
else down+=a[i-1]-a[i];
}
while(query--){
int l,r,x;
cin >> l >> r >> x;
int val=seg.get(1,0,node,l);
int val1=seg.get(1,0,node,l-1);
if(val>val1)up-=val-val1;
else down-=val1-val;
int val2,val3;
if(r<node){
val2=seg.get(1,0,node,r);
val3=seg.get(1,0,node,r+1);
if(val3>val2)up-=val3-val2;
else down-=val2-val3;
}
seg.update(1,0,node,l,r,x);
val=seg.get(1,0,node,l);
val1=seg.get(1,0,node,l-1);
if(val>val1)up+=val-val1;
else down+=val1-val;
if(r<node){
val2=seg.get(1,0,node,r);
val3=seg.get(1,0,node,r+1);
if(val3>val2)up+=val3-val2;
else down+=val2-val3;
}
// cout <<up<<" "<<down<<" "<<down*t<<" "<<up*s<<'\n';
cout <<1LL*t*down-1LL*up*s<<'\n';
}
// cout << ans;
}
main()
{
srand(time(0));
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
#define task "aws"
if(fopen(task".inp","r")){
freopen(task".inp","r",stdin);
freopen(task".out","w",stdout);
}
int t=1;
// cin >> t;
while(t--){
solve();cout<<'\n';
}
look_memory;
look_time;
}
