// Born_To_Laugh - Hughie Do
#include <bits/stdc++.h>
#define alle(AC) AC.begin(), AC.end()
#define fi first
#define se second
using namespace std;
typedef long long ll;
[[maybe_unused]] const ll MOD = 998244353, INF = 1e9 + 7;
#define int ll
const int maxn = 2e5 + 10;
struct Fenwick_Tree
{
vector<int> bit;
int n;
Fenwick_Tree(){
n = maxn - 1;
bit.assign(n + 1, 0);
}
void PointUpd(int pos, int val){
for(; pos<=n; pos += pos & -pos)bit[pos] += val;
}
int get(int pos){
int ans = 0;
for(; pos>0; pos -= pos & -pos)ans += bit[pos];
return ans;
}
};
Fenwick_Tree ft;
int n, q, s, t;
int ori[maxn];
ll ans = 0;
void solve(){
cin >> n >> q >> s >> t;
for(int i=1; i<=n + 1; ++i){
cin >> ori[i];
ft.PointUpd(i, ori[i] - ori[i - 1]);
if(i == 1)continue;
if(ori[i - 1] < ori[i]) ans += (ori[i - 1] - ori[i]) * s;
else ans += (ori[i - 1] - ori[i]) * t;
}
while(q--){
int l, r, x;cin >> l >> r >> x;
l++;r++;
if(l != 1){
int val = ft.get(l);
int nxt = val + x;
int pre = ft.get(l - 1);
int cc1, cc2;
if(pre < val)cc1 = (pre - val) * s;
else cc1 = (pre - val) * t;
if(pre < nxt)cc2 = (pre - nxt) * s;
else cc2 = (pre - nxt) * t;
ans += (cc2 - cc1);
ft.PointUpd(l, x);
}
if(r != n + 1){
int val = ft.get(r + 1);
int nxt = val - x;
int pre = ft.get(r);
int cc1, cc2;
if(pre < val)cc1 = (pre - val) * s;
else cc1 = (pre - val) * t;
if(pre < nxt)cc2 = (pre - nxt) * s;
else cc2 = (pre - nxt) * t;
ans += (cc2 - cc1);
ft.PointUpd(r + 1, -x);
}
cout << ans << '\n';
}
}
signed main(){
// freopen("inp.txt", "r", stdin);
// freopen("out.txt", "w", stdout);
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
solve();
}
