#include <bits/stdc++.h>
#define DEBUG 1
using namespace std;
namespace output{
void __(short x){cout<<x;}
void __(unsigned x){cout<<x;}
void __(int x){cout<<x;}
void __(long long x){cout<<x;}
void __(unsigned long long x){cout<<x;}
void __(double x){cout<<x;}
void __(long double x){cout<<x;}
void __(char x){cout<<x;}
void __(const char*x){cout<<x;}
void __(const string&x){cout<<x;}
void __(bool x){cout<<(x?"true":"false");}
template<class S,class T>
void __(const pair<S,T>&x){__(DEBUG?"(":""),__(x.first),__(DEBUG?", ":" "),__(x.second),__(DEBUG?")":"");}
template<class T>
void __(const vector<T>&x){__(DEBUG?"{":"");bool _=0;for(const auto&v:x)__(_?DEBUG?", ":" ":""),__(v),_=1;__(DEBUG?"}":"");}
template<class T>
void __(const set<T>&x){__(DEBUG?"{":"");bool _=0;for(const auto&v:x)__(_?DEBUG?", ":" ":""),__(v),_=1;__(DEBUG?"}":"");}
template<class T>
void __(const multiset<T>&x){__(DEBUG?"{":"");bool _=0;for(const auto&v:x)__(_?DEBUG?", ":" ":""),__(v),_=1;__(DEBUG?"}":"");}
template<class S,class T>
void __(const map<S,T>&x){__(DEBUG?"{":"");bool _=0;for(const auto&v:x)__(_?DEBUG?", ":" ":""),__(v),_=1;__(DEBUG?"}":"");}
void pr(){cout<<"\n";}
template<class S,class... T>
void pr(const S&a,const T&...b){__(a);if(sizeof...(b))__(' ');pr(b...);}
}
using namespace output;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef pair<double,double> pdd;
typedef pair<ld,ld> pld;
typedef vector<int> vi;
typedef vector<ll> vl;
#define pb push_back
#define fox(i,x,y) for(int i=(x);i<=(y);i++)
#define foxr(i,x,y) for(int i=(y);i>=(x);i--)
const ll MN = 2e5+5;
ll N, Q, S, T, A[MN], arr[MN], x, y, k, i, ans;
int main(){
scanf("%lld%lld%lld%lld",&N,&Q,&S,&T);
for(i=0;i<=N;i++) scanf("%lld",&A[i]);
for(i=1;i<=N;i++){
arr[i]=A[i-1]-A[i];
ans+=arr[i]>=0?arr[i]*T:arr[i]*S;
}
for(;Q;Q--){
scanf("%lld%lld%lld",&x,&y,&k); y++; k*=-1; ll kk = k;
if(arr[x]<=0){
if(k>=0){
ll D = min(-arr[x],k);
k -= D; arr[x] += D; ans += S*D;
if(k) arr[x]+=k, ans += T*k;
}
else arr[x]+=k, ans += S*k;
}
else{
if(k<=0){
ll D = min(arr[x],-k);
k += D, arr[x] -= D; ans -= T*D;
if(k) arr[x]+=k, ans += S*k;
}
else arr[x]+=k, ans += T*k;
}
if(y==N+1){
printf("%lld\n",ans);
continue;
}
x = y; k = -kk;
if(arr[x]<=0){
if(k>=0){
ll D = min(-arr[x],k);
k -= D; arr[x] += D; ans += S*D;
if(k) arr[x]+=k, ans += T*k;
}
else arr[x]+=k, ans += S*k;
}
else{
if(k<=0){
ll D = min(arr[x],-k);
k += D, arr[x] -= D; ans -= T*D;
if(k) arr[x]+=k, ans += S*k;
}
else arr[x]+=k, ans += T*k;
}
printf("%lld\n",ans);
}
return 0;
}
