#include <bits/stdc++.h>
#include <fstream>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
template<class T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
struct custom_hash {static uint64_t splitmix64(uint64_t x) {x += 0x9e3779b97f4a7c15;x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;x = (x ^ (x >> 27)) * 0x94d049bb133111eb;return x ^ (x >> 31);}size_t operator()(uint64_t x) const {static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();return splitmix64(x + FIXED_RANDOM);}};
// string __fname = ""; ifstream in (__fname + ".in"); ofstream out (__fname + ".out");
// #define cin in
// #define cout out
#define int64 long long
#define uint64 unsigned long long
#define x first
#define y second
#define pb push_back
#define pii pair <int, int>
#define pii64 pair <int64, int64>
#define db(x) cout << "> " << #x << ": " << (x) << "\n"
#define qr queries()
#define yn(x) if (x) {ctn("Yes");}else {ctn("No");}
void solve(int);
void queries(){int n;cin >> n;for (int i = 1; i <= n; i++) solve(i);}
template<class T>T ceildiv(T a, T b) {return a / b + !!(a % b);}
template<class T>T gcd (T a, T b){return (b ? gcd(b, a % b): a);}
template<class T>T lcm (T a, T b){return a * b / gcd(a, b);}
// // // // // // // // // // // // // // // // // // // // // //
/* TEMPLATE - VANILLA */
// // // // // // // // // // // // // // // // // // // // // //
const int ddx[] = {-1, -1, 0, 1, 1, 1, 0, -1};
const int ddy[] = {0, 1, 1, 1, 0, -1, -1, -1};
const int dx[] = {-1, 0, 1, 0};
const int dy[] = {0, 1, 0, -1};
const double pi = 3.14159265359;
const double eps = 1e-6;
const int64 hash_inv = 940594066;
const int64 hash_p = 101;
const int64 mod = 1e9 + 7;
const int maxn = 2e5 + 2;
int64 a[maxn];
int64 diff [maxn];
void solve(int id){
return;
}
int main(){
ios_base::sync_with_stdio(0); cin.tie(0); cout << fixed; cout << setprecision(10);
int n,m,s,t;
cin >> n >> m >> s >> t;
int64 inc = 0, dec = 0;
for (int i = 0; i <= n; i++) cin >> a[i];
for (int i = 1; i <= n; i++) {
diff[i] = a[i] - a[i-1];
if (diff[i] > 0) inc+=diff[i];
else dec-=diff[i];
}
// cout << inc << " " << dec << "\n";
while (m--) {
int64 l,r,v;
cin >> l >> r >> v;
if (diff[l] > 0) inc-=diff[l];
else dec+=diff[l];
diff[l]+=v;
if (diff[l] > 0) inc+=diff[l];
else dec-=diff[l];
if (diff[r + 1] > 0) inc-=diff[r + 1];
else dec+=diff[r + 1];
if (r != n) diff[r + 1]-=v;
if (diff[r + 1] > 0) inc+=diff[r + 1];
else dec-=diff[r + 1];
cout << inc * -s + dec * t << "\n";
}
return 0;
}
