// #pragma GCC diagnostic warnig "-std=c++11"
// #pragma GCC optimize("Ofast")
// #pragma GCC optimize ("O3")
// #pragma GCC optimization ("unroll-loops")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,fma")
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define eb emplace_back
#define mp make_pair
#define pb push_back
#define pp pop_back
#define endl '\n'
#define ff first
#define ss second
#define stop exit(0)
#define sz(x) (int)x.size()
#define pause system("pause")
#define all(x) (x).begin(),(x).end()
#define deb(x) cout << #x << "-" << x << endl
typedef char chr;
typedef string str;
typedef long long ll;
typedef vector <int> vii;
typedef pair <int,int> pii;
const long long INF = LLONG_MAX;
const int inf = INT_MAX;
const int mod = 998244353;
const int MOD = 1e9 + 7;
const int dx[] = {0,0,-1,1};
const int dy[] = {-1,1,0,0};
const double PI = 2 * acos(0.0);
const int N = 2e5 + 5;
int n,q,s,t,l,r,x,ans,a[N],b[N];
inline void test_case () {
cin >> n >> q >> s >> t;
for (int i = 0; i <= n; i++) {
cin >> a[i];
b[i] = a[i]-a[i-1];
if (b[i]>0) {
ans -= abs(b[i]) * s;
} else {
ans += abs(b[i]) * t;
}
}
// for (int i = 1; i <= n; i++) {
// cout << b[i] << " ";
// }
// cout << endl;
while (q--) {
cin >> l >> r >> x;
if (b[l]>0) {
ans += abs(b[l]) * s;
} else {
ans -= abs(b[l]) * t;
}
if (r < n) {
if (b[r+1]>0) {
ans += abs(b[r+1]) * s;
} else {
ans -= abs(b[r+1]) * t;
}
}
b[l] += x;
b[r+1] -= x;
if (b[l]>0) {
ans -= abs(b[l]) * s;
} else {
ans += abs(b[l]) * t;
}
if (r < n) {
if (b[r+1]>0 ) {
ans -= abs(b[r+1]) * s;
} else {
ans += abs(b[r+1]) * t;
}
}
// for (int i = 1; i <= n; i++) {
// cout << b[i] << " ";
// }
// cout << endl;
cout << ans << endl;
}
}
signed main () {
ios_base :: sync_with_stdio(0);
cin.tie(0); cout.tie(0);
int T = 1;
// cin >> T;
while(T--) {
test_case();
}
return 0;
}
