#include <iostream>
#include <vector>
#include <tuple>
#include <queue>
#include <stack>
#include <deque>
#include <set>
#include <map>
#include <cmath>
#include <array>
#include <random>
#include <string>
#include <cassert>
#include <climits>
#include <algorithm>
#include <unordered_set>
#include <unordered_map>
using namespace std;
#define ll long long
#define f first
#define s second
void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\'' << x << '\''; }
void __print(const char *x) { cerr << '\"' << x << '\"'; }
void __print(const string &x) { cerr << '\"' << x << '\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }
template<typename A> void __print(const A &x);
template<typename A, typename B> void __print(const pair<A, B> &p);
template<typename... A> void __print(const tuple<A...> &t);
template<typename T> void __print(stack<T> s);
template<typename T> void __print(queue<T> q);
template<typename T, typename... U> void __print(priority_queue<T, U...> q);
template<typename A> void __print(const A &x) {
bool first = true;
cerr << '{';
for (const auto &i : x) {
cerr << (first ? "" : ","), __print(i);
first = false;
}
cerr << '}';
}
template<typename A, typename B> void __print(const pair<A, B> &p) {
cerr << '(';
__print(p.f);
cerr << ',';
__print(p.s);
cerr << ')';
}
template<typename... A> void __print(const tuple<A...> &t) {
bool first = true;
cerr << '(';
apply([&first] (const auto &...args) { ((cerr << (first ? "" : ","), __print(args), first = false), ...); }, t);
cerr << ')';
}
template<typename T> void __print(stack<T> s) {
vector<T> debugVector;
while (!s.empty()) {
T t = s.top();
debugVector.push_back(t);
s.pop();
}
reverse(debugVector.begin(), debugVector.end());
__print(debugVector);
}
template<typename T> void __print(queue<T> q) {
vector<T> debugVector;
while (!q.empty()) {
T t = q.front();
debugVector.push_back(t);
q.pop();
}
__print(debugVector);
}
template<typename T, typename... U> void __print(priority_queue<T, U...> q) {
vector<T> debugVector;
while (!q.empty()) {
T t = q.top();
debugVector.push_back(t);
q.pop();
}
__print(debugVector);
}
void _print() { cerr << "]\n"; }
template <typename Head, typename... Tail> void _print(const Head &H, const Tail &...T) {
__print(H);
if (sizeof...(T)) cerr << ", ";
_print(T...);
}
#ifdef DEBUG
#define D(...) cerr << "Line: " << __LINE__ << " [" << #__VA_ARGS__ << "] = ["; _print(__VA_ARGS__)
#else
#define D(...)
#endif
struct Node {
int l, r;
ll s, lazy;
Node *lft, *rht;
Node (int tl, int tr, vector<int> &v): l(tl), r(tr), s(0), lazy(0) {
if (l + 1 != r) {
lft = new Node(l, (l + r) / 2, v);
rht = new Node((l + r) / 2, r, v);
} else {
lft = rht = NULL;
s = v[l];
}
}
};
void propagate(Node *x) {
if (x->lazy) {
x->lft->s += x->lazy * (x->lft->r - x->lft->l);
x->lft->lazy += x->lazy;
x->rht->s += x->lazy * (x->rht->r - x->rht->l);
x->rht->lazy += x->lazy;
x->lazy = 0;
}
}
void update(Node *x, int l, int r, ll v) {
if (r <= x->l || x->r <= l) {
return;
}
if (l <= x->l && x->r <= r) {
x->s += v * (x->r - x->l);
x->lazy += v;
return;
}
propagate(x);
update(x->lft, l, r, v);
update(x->rht, l, r, v);
x->s = x->lft->s + x->rht->s;
}
ll query(Node *x, int pos) {
if (pos < x->l || x->r <= pos) {
return 0;
}
if (x->l + 1 == x->r) {
return x->s;
}
propagate(x);
return query(x->lft, pos) + query(x->rht, pos);
}
int n, q;
ll s, t, ans;
vector<int> heights;
Node *root;
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cin >> n >> q >> s >> t;
for (int i = 0, x; i <= n; i++) {
cin >> x;
heights.push_back(x);
}
for (int i = 1; i <= n; i++) {
if (heights[i] > heights[i - 1]) {
ans -= (heights[i] - heights[i - 1]) * s;
} else {
ans += (heights[i - 1] - heights[i]) * t;
}
}
root = new Node(0, n + 1, heights);
for (int i = 0, l, r; i < q; i++) {
ll c; cin >> l >> r >> c;
if (l > 0) {
if (query(root, l) > query(root, l - 1)) {
ans += (query(root, l) - query(root, l - 1)) * s;
} else {
ans -= (query(root, l - 1) - query(root, l)) * t;
}
}
if (r < n) {
if (query(root, r + 1) > query(root, r)) {
ans += (query(root, r + 1) - query(root, r)) * s;
} else {
ans -= (query(root, r) - query(root, r + 1)) * t;
}
}
update(root, l, r + 1, c);
if (l > 0) {
if (query(root, l) > query(root, l - 1)) {
ans -= (query(root, l) - query(root, l - 1)) * s;
} else {
ans += (query(root, l - 1) - query(root, l)) * t;
}
}
if (r < n) {
if (query(root, r + 1) > query(root, r)) {
ans -= (query(root, r + 1) - query(root, r)) * s;
} else {
ans += (query(root, r) - query(root, r + 1)) * t;
}
}
cout << ans << "\n";
}
}
