#include <bits/stdc++.h>
#pragma GCC optimize("O3")
using namespace std;
#define ll long long
ll mod = 1e9+7;
//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
ll binpow(ll a, ll b)
{
ll res = 1;
while (b>0)
{
if (b&1)
res = (res*a)%mod;
a = (a*a)%mod;
b>>=1;
}
return res;
}
ll gcd(ll x, ll y)
{
if (y==0)
return x;
return gcd(y, x%y);
}
const ll mx = 800000;
ll a[mx];
ll st[4*mx];
ll vec[mx];
vector<ll>lazy(mx, 0);
void build (ll l, ll r, ll v)
{
if (l==r)
{
st[v] = vec[l];
return;
}
ll mid = (l+r)/2;
build(l, mid, 2*v);
build(mid+1, r, 2*v+1);
st[v] = st[2*v] + st[2*v+1];
}
void push(ll l, ll r, ll v)
{
if (lazy[v]==0) return;
st[v]+=lazy[v]*(r-l+1);
if (l!=r)
{
lazy[2*v] += lazy[v];
lazy[2*v+1] += lazy[v];
}
lazy[v] = 0;
}
ll getsum (ll l, ll r, ll v, ll ql, ll qr)
{
push(l, r, v);
if (r<ql or l>qr)
return 0;
if (l>=ql and r<=qr)
return st[v];
ll mid = (l+r)/2;
return getsum(l, mid, 2*v, ql, qr) + getsum(mid+1, r, 2*v+1, ql, qr);
}
void update(ll l, ll r, ll v, ll ql, ll qr, ll val)
{
if (r<ql or l>qr)
return;
push(l, r, v);
if (l>=ql and r<=qr)
{
lazy[v] += val;
push(l, r, v);
return;
}
ll mid = (l+r)/2;
update(l, mid, 2*v, ql, qr, val);
update(mid+1, r, 2*v+1, ql, qr, val);
st[v] = st[2*v]+st[2*v+1];
}
void solve()
{
ll n,q,s,t;
cin>>n>>q>>s>>t;
swap(s, t);
for (int i=0 ; i<=n ;i++)
cin>>vec[i];
build(1, n, 1);
ll res = 0;
for (int i=0 ; i<n ;i++)
{
if (vec[i+1]>vec[i])
res -= t*(vec[i+1]-vec[i]);
else
res += s*(vec[i]-vec[i+1]);
}
//cout<<res<<endl;
while (q--)
{
ll x, y, z;
cin>>x>>y>>z;
vec[x] = getsum(1, n, 1, x, x);
vec[x-1] = getsum(1, n, 1, x-1, x-1);
vec[y] = getsum(1, n, 1, y, y);
if (vec[x-1]<vec[x]) res += t*(vec[x]-vec[x-1]);
else res -= s*(vec[x-1]-vec[x]);
if (y!=n)
{
vec[y+1] = getsum(1, n, 1, y+1, y+1);
if (vec[y+1]>vec[y]) res += t*(vec[y+1]-vec[y]);
else res -= s*(vec[y]-vec[y+1]);
}
update(1, n, 1, x, y, z);
vec[x] = getsum(1, n, 1, x, x);
vec[x-1] = getsum(1, n, 1, x-1, x-1);
vec[y] = getsum(1, n, 1, y, y);
if (vec[x-1]<vec[x]) res -= t*(vec[x]-vec[x-1]);
else res += s*(vec[x-1]-vec[x]);
if (y!=n)
{
vec[y+1] = getsum(1, n, 1, y+1, y+1);
if (vec[y+1]>vec[y]) res -= t*(vec[y+1]-vec[y]);
else res += s*(vec[y]-vec[y+1]);
}
cout<<res<<endl;
}
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
ll tt = 1;
// cin>>tt;
while (tt--)
{
solve();
}
return 0;
}
