#include <bits/stdc++.h>
using namespace std;
#define in ({int x=0;int c=getchar(),n=0;for(;!isdigit(c);c=getchar()) n=(c=='-');for(;isdigit(c);c=getchar()) x=x*10+c-'0';n?-x:x;})
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int rnd(int l,int r){return l+rng()%(r-l+1);}
#define fasty ios_base::sync_with_stdio(false),cin.tie(nullptr);
#define task "Foehn"
#define forinc(a,b,c) for(int a=b,_c=c;a<=_c;++a)
#define fordec(a,b,c) for(int a=b,_c=c;a>=_c;--a)
#define forv(a,b) for(auto&a:b)
#define gg exit(0)
#define fi first
#define se second
#define pb push_back
#define ii pair<int,int>
#define mt make_tuple
#define all(a) a.begin(),a.end()
#define reset(f, x) memset(f, x, sizeof(f))
#define bit(x,i) ((x>>(i-1))&1)
#define on(x,i) (x|(1ll<<(i-1)))
#define off(x,i) (x&~(1<<(i-1)))
main(){
//freopen(task".inp","r",stdin);
//freopen(task".out","w",stdout);
#define int long long
int n=in,q=in,s=in,t=in,tmp=0;
vector<int> a(n+1),b(n+1);
forinc(i,0,n) a[i]=in;
auto eval=[&](int i){
return i<0 ? i*s : i*t;
};
forinc(i,1,n){
b[i]=a[i-1]-a[i];
tmp+=eval(b[i]);
}
forinc(i,1,q){
int l=in,r=in,x=in;
if(l){
tmp-=eval(b[l]);
b[l]-=x;
tmp+=eval(b[l]);
}
if(r<n){
tmp-=eval(b[r+1]);
b[r+1]+=x;
tmp+=eval(b[r+1]);
}
cout<<tmp<<"\n";
}
}
