#include <bits/stdc++.h>
using namespace std;
int t = 0;
int const f = 2e5 + 10;
long long mod = 1e9 + 7;//998244353;
long long A[f];
int dp1[f];
int dp2[500000+10];
int fact[500000+10];
vector<int> prime;
vector<int> ds[500000+10];
int inds[f];
vector<int> dsu[f];
int par[f];
struct node {
long long val = 0;
long long lazy = 0;
};
node segtree[8*f];
struct trpel{
long long v,u,bank =0;
};
bool B[f];
void redany() {
ifstream fin;
ofstream fout;
fin.open("input.txt");
fout.open("output.txt");
}
long long powmod(long long a, long long p, long long modd) {
long long ans = 1;
while (p > 0) {
if (p % 2 == 1) {
ans *= a;
ans %= modd;
p--;
}
if (p == 0)break;
a *= a;
a %= modd;
p /= 2;
}
return ans;
}
void dolazy(int v, int l , int r){
int mid = (l+r)/2;
long long cnt = segtree[v].lazy;
segtree[2*v].lazy+=cnt;
segtree[2*v+1].lazy+=cnt;
segtree[2*v].val+=cnt*(mid-l+1);
segtree[2*v+1].val+=cnt*(r-mid);
segtree[v].lazy = 0;
}
void build(int v , int l , int r){
if(l==r){
segtree[v].val = A[r];
return;
}
int mid = (r+l)/2;
build(2*v,l, mid);
build(2*v+1,mid+1,r);
segtree[v].val = segtree[2*v].val+segtree[2*v+1].val;
}
void upd(int v, int tl, int tr, int l , int r, int val){
if(tr<l||tl>r)return;
if(tr<=r&&tl>=l){
segtree[v].val+=val;
segtree[v].lazy+=val;
return;
}
dolazy(v,tl,tr);
int mid = (tl+tr)/2;
upd(2*v,tl,mid,l,r,val);
upd(2*v+1,mid+1,tr,l,r,val);
segtree[v].val = segtree[2*v].val+segtree[2*v+1].val;
}
long long q(int v, int tl, int tr, int pos){
if(tl==tr&&tr==pos){
return segtree[v].val;
}
dolazy(v, tl, tr);
int mid = (tl+tr)/2;
if(pos>mid){
return q(2*v+1,mid+1,tr,pos);
}
else{
return q(2*v,tl,mid,pos);
}
}
long long comb(long long n, long long k){
return ((fact[n]*powmod(fact[k],mod-2,mod))%mod*powmod(fact[n-k],mod-2,mod))%mod;
}
int main() {
ios::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
//cin >> t;
t = 1;
for (int hhh = 1;hhh <= t;hhh++) {
long long n, mx = 0, d = 0, m = 0, k = 0, k2 = 0, r = 0, rr = 0, l = 0, ll = 0, lll = 0, rrr = 0, inf = 1e18;
string s1;
string s3;
char s2;
long long dec = 1;
bool c = 1;
priority_queue<pair<long long, long long>> qq;
queue<int> pp;
map<pair<int,pair<int,int>>, long long> conv;
vector<long long> vec;
cin >> n>>m>>k>>d;
for(int i =0;i<n+1;i++){
cin>>A[i];
}
build(1,0,n);
for(int i =0;i<n;i++){
if(A[i+1]>A[i]){
mx-=(A[i+1]-A[i])*k;
B[i] =1;
}
else{
mx+=(A[i]-A[i+1])*d;
B[i] =0;
}
}
//cout<<mx<<'\n';
for(int i =0;i<m;i++){
cin>>l>>r>>k2;
ll = q(1,0,n,l-1);
lll = q(1,0,n,l);
//cout<<ll<<" "<<lll<<'\n';
if(lll>ll){
mx+=(lll-ll)*k;
// cout<<"added "<<(lll-ll)*k<<'\n';
}
else{
mx-=(ll-lll)*d;
// cout<<"losed "<<(lll-ll)*d<<'\n';
}
if(r!=n){
ll = q(1,0,n,r);
lll = q(1,0,n,r+1);
// cout<<"2 :"<<ll<<" "<<lll<<'\n';
if(lll>ll){
mx+=(lll-ll)*k;
//cout<<"added "<<(lll-ll)*k<<'\n';
}
else{
mx-=(ll-lll)*d;
//cout<<"losed "<<(lll-ll)*d<<'\n';
}
}
upd(1,0,n,l,r,k2);
ll = q(1,0,n,l-1);
lll = q(1,0,n,l);
//cout<<":: "<<ll<<" "<<lll<<'\n';
if(lll>ll){
mx-=(lll-ll)*k;
// cout<<"losed 2 "<<(lll-ll)*k<<'\n';
}
else{
mx+=(ll-lll)*d;
// cout<<"added 2 "<<(lll-ll)*d<<'\n';
}
if(r!=n){
ll = q(1,0,n,r);
lll = q(1,0,n,r+1);
// cout<<":: 2 :"<<ll<<" "<<lll<<'\n';
if(lll>ll){
mx-=(lll-ll)*k;
// cout<<"losed 2 "<<(lll-ll)*k<<'\n';
}
else{
mx+=(ll-lll)*d;
// cout<<"added 2 "<<(lll-ll)*d<<'\n';
}
}
cout<<mx<<'\n';
}
}
}
