#include <bits/stdc++.h>
using namespace std;
#define int long long
vector<int>st(8*200000);
vector<int>lazy(8*200000);
int l,r,x;
int query(int i, int j, int p) {
if(i > l || j < l)
return 0;
if(i == j) {
st[p] += lazy[p];
lazy[p] = 0;
return st[p];
}
lazy[2*p] += lazy[p];
lazy[2*p+1] += lazy[p];
lazy[p] = 0;
int mid = (i+j)/2;
return query(i, mid, 2*p) + query(mid+1, j, 2*p+1);
}
void update(int i, int j, int p) {
if(i > r || j < l)
return;
if(i >= l && j <= r) {
lazy[p] += x;
return;
}
int mid = (i+j)/2;
update(i, mid, 2*p);
update(mid+1, j, 2*p+1);
}
signed main() {
int n,q,s,t; cin>>n>>q>>s>>t;
vector<int>v(n+1);
for(auto &z : v)
cin>>z;
long long ans = 0;
for(int i = 1 ; i <= n ; i++) {
x = v[i];
l = r = i;
update(1, n, 1);
if(v[i] > v[i-1])
ans -= (v[i]-v[i-1]) * s;
else
ans += (v[i-1]-v[i]) * t;
}
while(q--) {
cin>>l>>r>>x;
int L = l, R = r;
int A = query(1, n, 1);
l = R;
int B = query(1, n, 1);
l = L-1;
int a = (l == 0 ? 0 : query(1, n, 1));
l = R+1;
int b = (l == n+1 ? 0 : query(1, n, 1));
l = L, r = R;
update(1, n, 1);
l = L;
int nwA = query(1, n, 1);
l = R;
int nwB = query(1, n, 1);
if(A >= a)
ans += (A - a) * s;
else
ans -= (a - A) * t;
if(nwA >= a)
ans -= (nwA - a) * s;
else
ans += (a - nwA) * t;
if(R < n) {
if(b >= B)
ans += (b - B) * s;
else
ans -= (B - b) * t;
if(b >= nwB)
ans -= (b - nwB) * s;
else
ans += (nwB - b) * t;
}
cout << ans << '\n';
}
}
