#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
#pragma GCC optimize("Ofast,unroll-loops,fast-math")
#pragma GCC target("popcnt")
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<ll,ll> pll;
#define sz size()
#define ff first
#define ss second
#define all(a) a.begin(),a.end()
#define pb push_back
const int mod = ll(1e9)+7; //(b + (a%b)) % b (to mod -1%(10^9+7) correctly in c++ its -1 but its suppose to be 10^9+6
const ll MOD = 998244353; // (a%mod)*(binpow(b,mod-2,mod) = (a/b)%mod
const int N = ll(2e5)+100;
const int M = ll(2e5) + 100;
const long long inf = 5e18;
const long double eps = 1e-15L;
ll lcm(ll a, ll b) { return (a / __gcd(a,b))*b; }
ll binpow(ll a, ll b, ll m) { ll res=1; a %= m; while(b>0){ if(b&1)res=(res * a) % m; a=(a * a) % m; b/=2; } return res%m;}
void Freopen(string Key){ freopen((Key+".in").c_str(), "r", stdin); freopen((Key+".out").c_str(), "w", stdout); }
int n, q, s, t, a[N];
long long ans = 0, u[N * 4];
long long val(long long x, long long y, int p) {
if(p == n + 1) return 0;
if(x < y) return 1LL * (x - y) * s;
return 1LL * (x - y) * t;
}
void update(int v, int tl, int tr, int l, int r, int x) {
if(tl > r || l > tr) return;
if(l <= tl && tr <= r) {
u[v] += x;
return;
}
int tm = (tl + tr) / 2;
update(v + v, tl, tm, l, r, x);
update(v + v + 1, tm + 1, tr, l, r, x);
}
long long get(int v, int tl, int tr, int p) {
if(tl == tr) return u[v];
int tm = (tl + tr) / 2;
if(p <= tm) return get(v + v, tl, tm, p) + u[v];
else return get(v + v + 1, tm + 1, tr, p) + u[v];
}
void Baizho() {
cin>>n>>q>>s>>t;
for(int i = 0; i <= n; i ++) {
cin>>a[i];
update(1, 0, n, i, i, a[i]);
}
for(int i = 0; i < n; i ++) {
ans += val(a[i], a[i + 1], i + 1);
}
while(q --) {
int l, r, x; cin>>l>>r>>x;
long long v1 = get(1, 0, n, l - 1), v2 = get(1, 0, n, l), v3 = get(1, 0, n, r), v4 = get(1, 0, n, r + 1);
ans = ans - val(v1, v2, l) - val(v3, v4, r + 1) + val(v1, v2 + x, l) + val(v3 + x, v4, r + 1);
update(1, 0, n, l, r, x);
cout<<ans<<"\n";
}
}
signed main() {
// Freopen("nondec");
ios_base::sync_with_stdio(false);
cin.tie(0);cout.tie(0);
// precalc();
int ttt = 1;
// cin>>ttt;
for(int i=1; i<=ttt; i++) {Baizho(); }
}
