#include "bits/stdc++.h"
using namespace std;
#define forR(i, x) for(int i=0; i<(x); ++i)
#define REP(i, a, b) for(int i=(a); i<(b); ++i)
#define all(x) x.begin(), x.end()
#define boost() cin.sync_with_stdio(0); cin.tie(0)
typedef long long ll;
typedef vector<int> vi;
const int MN = 2e5 + 10;
ll bit[MN];
void upd(int i, ll by) {
++i;
for(; i < MN; i+=i&-i) bit[i] += by;
}
ll qu(int i) {
++i;
ll tot = 0;
for(; i > 0; i-=i&-i) tot += bit[i];
return tot;
}
signed main() {
boost();
int n, q; ll s, t; cin >> n >> q >> s >> t;
ll tot = 0;
forR(i, n+1) {
ll v; cin >> v;
upd(i, v - (i == 0 ? 0 : qu(i-1)));
}
REP(i, 1, n+1) {
ll ac = qu(i), ap=qu(i-1);
if(ac > ap) tot -= s * (ac-ap);
else tot += t * (ap - ac);
}
forR(j, q){
int l, r; ll x; cin >> l >> r >> x;
if(l > 0){
ll ac=qu(l), ap=qu(l-1);
if(ac > ap) tot += s * (ac-ap);
else tot -= t * (ap - ac);
ll na = ac + x;
if(na > ap) tot -= s * (na-ap);
else tot += t * (ap - na);
}
if(r < n){
ll ac=qu(r+1), ap=qu(r);
if(ac > ap) tot += s * (ac-ap);
else tot -= t * (ap-ac);
ll na = ap + x;
if(ac > na) tot -= s * (ac-na);
else tot += t * (na-ac);
}
upd(l, x);
upd(r+1, -x);
cout << tot << '\n';
}
}
