#include <bits/stdc++.h>
#define pii pair<int, int>
#define mp make_pair
#define F first
#define S second
#define PB push_back
#define FOR(i, u, v) for (int i = u; i <= v; i++)
#define FORD(i, v, u) for (int i = v; i >= u; i--)
#define ll long long
#define mid (r + l)/2
#define N 2000005
#define LN 19
#define maxc 1000000007
using namespace std;
int n, numQ, S, T;
ll valUp, valDown;
struct BIT
{
ll t[N];
void upd(int x, ll val)
{
for (; x < N; x += (x & -x)) t[x] += val;
}
void upd(int l, int r, ll val)
{
upd(l, val);
upd(r+1, -val);
}
ll get(int x)
{
ll ans = 0;
for (; x; x -= (x & -x)) ans += t[x];
return ans;
}
}t;
void update(int u, int sign)
{
if (u == n) return;
ll val = 0;
ll x = t.get(u);
ll y = t.get(u+1);
if (x < y) valUp += sign*abs(y-x);
else valDown += sign*abs(y-x);
}
int main()
{
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
//freopen("INP.TXT", "r", stdin);
cin >> n >> numQ >> S >> T; n++;
FOR(i, 1, n)
{
int x; cin >> x;
t.upd(i, i, x);
}
FOR(i, 1, n-1) update(i, 1);
while (numQ--)
{
int u, v, val; cin >> u >> v >> val; u++; v++;
update(u-1, -1);
update(v, -1);
t.upd(u, v, val);
update(u-1, 1);
update(v, 1);
cout <<valDown*T - valUp*S<<'\n';
}
}
