#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
using namespace std;
#define int long long
#define nl '\n'
#define io ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0)
const int mod = 1000000007, mod2 = 998244353;
// change this
const int N = 200005;
int n, q, s, t, arr[N], ans;
int delta(int x, int y) {
if (x < y) return -s * (y-x);
else return t * (x-y);
}
int fw[N], fw2[N];
void update(int x, int y, int v) { //inclusive
for (int tx=x; tx < N; tx += tx&(-tx)) fw[tx] += v, fw2[tx] -= v*(x-1);
for (int ty=y+1; ty < N; ty += ty&(-ty)) fw[ty] -= v, fw2[ty] += v*y;
}
int sum (int x) {
int res = 0;
for (int tx=x; tx; tx -= tx&(-tx)) res += fw[tx]*x + fw2[tx];
return res;
}
int point(int x) { //inclusive
if (x == 0) return 0;
return sum(x) - sum(x-1);
}
signed main() {
io;
cin >> n >> q >> s >> t;
n++;
for (int i=0; i<n; i++) {
cin >> arr[i];
if (i) update(i, i, arr[i]);
}
for (int i=1; i<n; i++) {
ans += delta(arr[i-1], arr[i]);
}
while (q--) {
int a, b, c;
cin >> a >> b >> c;
int dx = delta(point(a-1), point(a) + c) - delta(point(a-1), point(a));
int dy = delta(point(b) + c, point(b+1)) - delta(point(b), point(b+1));
update(a, b, c);
if (b == n-1) dy = 0;
cout << (ans += dx + dy) << nl;
}
}
