#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ar array
typedef pair<int, int> pi;
const int mxN = 2e5+5, M = 1e9+7;
ll n, q, s, t;
struct SEG{
ll ans[4*mxN], rval[4*mxN], lval[4*mxN], lazy[4*mxN];
void init(){
memset(ans, 0, sizeof(ans));
memset(rval, 0, sizeof(rval));
memset(lval, 0, sizeof(lval));
memset(lazy, 0, sizeof(lazy));
}
void push(int i){
rval[2*i] += lazy[i];
lval[2*i] += lazy[i];
lazy[2*i] += lazy[i];
rval[2*i+1] += lazy[i];
lval[2*i+1] += lazy[i];
lazy[2*i+1] += lazy[i];
lazy[i] = 0;
}
void merge(int i){
rval[i] = rval[2*i+1];
lval[i] = lval[2*i];
ans[i] = ans[2*i] + ans[2*i+1];
if(rval[2*i] < lval[2*i+1]){
ans[i] += s*(lval[2*i+1]-rval[2*i]);
}else{
ans[i] -= t*(rval[2*i]-lval[2*i+1]);
}
}
void upd(int l1, int r1, int l2, int r2, int i, ll val){
if(r1 < l2 || r2 < l1) return;
if(l1 <= l2 && r2 <= r1){
rval[i]+=val;
lval[i]+=val;
lazy[i]+=val;
return;
}
int m2 = (l2+r2)/2;
push(i);
upd(l1, r1, l2, m2, 2*i, val);
upd(l1, r1, m2+1, r2, 2*i+1, val);
merge(i);
}
void print(int l1, int r1, int i){
if(l1 == r1){
cout << lval[i] << " ";
return;
}
int m1 = (l1+r1)/2;
print(l1, m1, 2*i);
print(m1+1, r1, 2*i+1);
}
}seg;
int main(){
#ifdef _DEBUG
// freopen("input.txt", "r", stdin);
// freopen("output.txt", "w", stdout);
#endif
std::ios_base::sync_with_stdio(false); std::cin.tie(0); std::cout.tie(0);
cin >> n >> q >> s >> t;
seg.init();
//seg.print(0, n, 1);
//cout << " here\n";
for(int i = 0; i<=n; ++i){
ll x;
cin >> x;
seg.upd(i, i, 0, n, 1, x);
}
//seg.print(0, n, 1);
//cout << "\n";
while(q--){
int a, b;
ll c;
cin >> a >> b >> c;
seg.upd(a, b, 0, n, 1, c);
// seg.print(0, n, 1);
// cout << "\n";
cout << -seg.ans[1] << "\n";
}
}
