/** author : _RAIN_ **/
#include<bits/stdc++.h>
using namespace std;
using i64 = long long;
using ui64 = unsigned long long;
#define MASK(x) ((i64)(1) << (x))
#define BIT(mask , x) (((mask) >> (x)) & (1))
template<class T>
bool maximize(T &a , T b) {if (a < b) return a = b , true; else return false;}
template<class T>
bool minimize(T &a , T b) {if (a > b) return a = b , true; else return false;}
template<class T>
T gcd(T x , T y) {while (y) swap(y , x %= y); return x;}
template<class T>
T lcm(T x , T y) {return (x * y) / gcd(x , y);}
const int maxn = 2e5;
int numhouse , q ;
int a[maxn + 2];
i64 s , t;
class interval
{
public:
struct NODE
{
i64 lazy;
i64 val;
};
vector<NODE> seg;
void init(int n)
{
seg.assign(n * 4 + 7 , {0 , 0});
}
void build(int node , int l , int r , int a[])
{
if (l == r)
seg[node].val = a[l];
else
{
int m = l + r >> 1;
build(node * 2 , l , m , a);
build(node * 2 + 1 , m + 1 , r , a);
seg[node].val = seg[node * 2].val + seg[node * 2 + 1].val;
}
return;
}
void pushdown(int node)
{
i64& t = seg[node].lazy;
seg[node * 2].val += t; seg[node * 2].lazy += t;
seg[node * 2 + 1].val += t; seg[node * 2 + 1].lazy += t;
t = 0;
return;
}
void update(int node , int l , int r , int u , int v , i64 k)
{
if (l > v || r < u) return;
if (u <= l && r <= v)
{
seg[node].val += k;
seg[node].lazy += k;
return;
}
int m = l + r >> 1;
pushdown(node);
update(node * 2 , l , m , u , v , k);
update(node * 2 + 1 , m + 1 , r , u , v , k);
}
i64 get(int node , int l , int r , int u , int v)
{
if (l > v || r < u) return 0;
if (u <= l && r <= v) return seg[node].val;
int m = l + r >> 1;
pushdown(node);
return get(node * 2 , l , m , u , v) + get(node * 2 + 1, m + 1 , r , u , v);
}
};
int32_t main(void)
{
cin.tie(nullptr)->sync_with_stdio(false);
const string name = "main";
if (fopen((name + ".inp").c_str() , "r"))
{
(void)!freopen((name + ".inp").c_str() , "r" , stdin);
(void)!freopen((name + ".out").c_str() , "w+", stdout);
}
cin >> numhouse >> q >> s >> t;
interval seg; seg.init(numhouse);
for (int i = 0; i <= numhouse; ++i)
cin >> a[i];
seg.build(1 , 0 , numhouse , a);
i64 answer = 0;
for (int i = 1; i <= numhouse; ++i)
{
if (a[i] > a[i - 1]) answer -= s * (a[i] - a[i - 1]);
if (a[i] <= a[i - 1]) answer += t * (a[i - 1] - a[i]);
}
auto cost = [&](int l , int r)->i64
{
i64 x = seg.get(1 , 0 , numhouse , l , l);
i64 y = seg.get(1 , 0 , numhouse , r , r);
return (i64)(x >= y ? t : -s) * abs(x - y);
};
while(q--)
{
int l , r , x; cin>>l>>r>>x;
if (l > 0) answer-= cost(l - 1 , l);
if (r < numhouse) answer-=cost(r , r + 1);
seg.update(1 , 0 , numhouse , l , r , x);
if (l > 0) answer+=cost(l - 1 , l);
if (r < numhouse) answer+=cost(r , r + 1);
cout<<answer<<'\n';
}
}
