//by szh
#include<bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define pii pair<int,int>
#define pll pair<long long,long long>
#define pb push_back
#define debug(x) cerr<<#x<<"="<<x<<endl
#define pq priority_queue
#define inf 0x3f
#define rep(i,a,b) for (int i=a;i<(b);i++)
#define MP make_pair
#define SZ(x) (int(x.size()))
#define ll long long
#define mod 1000000007
#define ALL(x) x.begin(),x.end()
void inc(int &a,int b) {a=(a+b)%mod;}
void dec(int &a,int b) {a=(a-b+mod)%mod;}
int lowbit(int x) {return x&(-x);}
ll p0w(ll base,ll p) {ll ret=1;while(p>0){if (p%2ll==1ll) ret=ret*base%mod;base=base*base%mod;p/=2ll;}return ret;}
const int maxn = 2e5+10;
ll n,_,s,t;
ll dif[maxn];
ll calc(ll x) {
if (x<0) return -x*t;
else return -x*s;
}
int main() {
// freopen("input.txt","r",stdin);
std::ios::sync_with_stdio(false);cin.tie(0);
cin>>n>>_>>s>>t;
int lst;
ll ans = 0;
rep(i,0,n+1) {
int x;cin>>x;
if (i!=0) dif[i] = x-lst,ans+=calc(dif[i]);
lst = x;
}
while (_--) {
ll l,r,delta;
cin>>l>>r>>delta;
if (l>0) {
ans -= calc(dif[l]);
dif[l]+=delta;
ans += calc(dif[l]);
}
if (r+1<=n) {
ans -= calc(dif[r+1]);
dif[r+1]-=delta;
ans += calc(dif[r+1]);
}
cout<<ans<<"\n";
}
return 0;
}
