#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define pb push_back
#define pii pair<int,int>
#define FOR(i, a, b) for(int i=(signed)(a); i<=(signed)(b); i++)
#define F0R(i, a) for(int i=(0); i<(signed)(a); i++)
const int MXN = 2e5 + 10;
ll arr[MXN] = {0};
ll updL[MXN] = {0};
ll updR[MXN] = {0};
int main(){
//faster io
ios_base::sync_with_stdio(false);
cin.tie(NULL);
ll N, Q, S, T;
cin>>N>>Q>>S>>T;
ll ans = 0;
cin>>arr[0]; //always zero
FOR(i, 1, N){
cin>>arr[i];
if(arr[i-1]<arr[i]){
ans -= S * abs(arr[i]-arr[i-1]);
}
else{
ans += T * abs(arr[i]-arr[i-1]);
}
}
// FOR(i, 1, N) cout<<arr[i]<<" ";
// cout<<"\n";
// cout<<"ans="<<ans<<"!";
ll L, R, X;
while(Q--){
cin>>L>>R>>X;
// upd[L]+=X;
if(((arr[L-1]+updR[L-1])<(arr[L]+updL[L])) &&
((arr[L-1]+updR[L-1])>=(arr[L]+updL[L]+X)))
{
ans += (S * abs((arr[L-1]+updR[L-1])-(arr[L]+updL[L])));
ans += (T * abs((arr[L-1]+updR[L-1])-(arr[L]+updL[L]+X)));
}
else if(((arr[L-1]+updR[L-1])>=(arr[L]+updL[L])) &&
((arr[L-1]+updR[L-1])<(arr[L]+updL[L]+X)))
{
ans-= (T * abs((arr[L-1]+updR[L-1])-(arr[L]+updL[L])));
ans-= (S * abs((arr[L-1]+updR[L-1])-(arr[L]+updL[L]+X)));
}
else{
if((arr[L-1]+updR[L-1])<(arr[L]+updL[L]+X)) ans -= (S*X);
else ans -= (T*X);
}
if(R==N){
updL[L]+=X;
// if(L!=R)
updR[R]+=X;
cout<<ans<<"\n";
continue;
}
if(((arr[R]+updR[R])<(arr[R+1]+updL[R+1])) &&
((arr[R]+updR[R]+X)>=(arr[R+1]+updL[R+1])))
{
ans+= (S * abs((arr[R]+updR[R])-(arr[R+1]+updL[R+1])));
ans+= (T * abs((arr[R]+updR[R]+X)-(arr[R+1]+updL[R+1])));
}
else if(((arr[R]+updR[R])>=(arr[R+1]+updL[R+1])) &&
((arr[R]+updR[R]+X)<(arr[R+1]+updL[R+1])))
{
ans-= (T * abs((arr[R]+updR[R])-(arr[R+1]+updL[R+1])));
ans-= (S * abs((arr[R]+updR[R]+X)-(arr[R+1]+updL[R+1])));
}
else{
if((arr[R]+updR[R]+X)<(arr[R+1]+updL[R+1])) ans += (S*X);
else ans += (T*X);
}
updL[L]+=X;
// if(L!=R)
updR[R]+=X;
cout<<ans<<"\n";
}
}
