#include <iostream>
#include <iomanip>
#include <cassert>
#include <vector>
#include <numeric>
#include <string>
#include <bitset>
#include <cmath>
#include <algorithm>
#include <stack>
#include <queue>
#include <deque>
#include <set>
#include <unordered_set>
#include <map>
#include <unordered_map>
#include <random>
#include <ctime>
#include <chrono>
using namespace std;
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define sz(x) (int)((x).size())
typedef unsigned int uint;
typedef long long ll;
typedef unsigned long long ull;
//typedef __int128_t int128;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const char en = '\n';
const int INF = 1e9 + 7;
const ll INFLL = 1e18;
mt19937 rnd(chrono::high_resolution_clock::now().time_since_epoch().count());
#ifdef __APPLE__
#include "debug.h"
//#define debug(...) 42
#else
#define debug(...) 42
#endif
ll s, t;
struct SegTree {
struct Node {
ll T, l, r, pushed;
};
int n, qL, qR, index;
ll val, ans;
const ll off = 0;
vector<Node> tree;
vector<ll> a;
SegTree(int _n) {
n = _n;
tree.assign(4 * n, {0, 0, 0, off});
}
void update_vertex(int v, int l, int r) {
int m = (l + r) / 2, vL = 2 * v, vR = vL + 1;
push(vL, l, m);
push(vR, m, r);
tree[v].T = tree[vL].T + tree[vR].T;
if (tree[vL].r < tree[vR].l) {
tree[v].T -= s * (tree[vR].l - tree[vL].r);
}
else if (tree[vL].r > tree[vR].l) {
tree[v].T += t * (tree[vL].r - tree[vR].l);
}
tree[v].l = tree[vL].l;
tree[v].r = tree[vR].r;
}
void push(int v, int l, int r) {
if (tree[v].pushed == off) return;
int m = (l + r) / 2, vL = 2 * v, vR = vL + 1;
tree[v].l += tree[v].pushed;
tree[v].r += tree[v].pushed;
if (l + 1 != r) {
tree[vL].pushed += tree[v].pushed;
tree[vR].pushed += tree[v].pushed;
}
tree[v].pushed = off;
}
void build(vector<ll> &_a) {
a = _a;
build_tree(1, 0, n);
}
void build_tree(int v, int l, int r) {
if (l + 1 == r) {
tree[v] = {0, a[l], a[l], off};
return;
}
int m = (l + r) / 2, vL = 2 * v, vR = vL + 1;
build_tree(vL, l, m);
build_tree(vR, m, r);
update_vertex(v, l, r);
}
void update_segment(int _qL, int _qR, ll _val) {
qL = _qL;
qR = _qR + 1;
val = _val;
update_segment_tree(1, 0, n);
}
void update_segment_tree(int v, int l, int r) {
push(v, l, r);
if (qL <= l && r <= qR) {
tree[v].pushed += val;
push(v, l, r);
return;
}
int m = (l + r) / 2, vL = 2 * v, vR = vL + 1;
if (qL < m) update_segment_tree(vL, l, m);
if (m < qR) update_segment_tree(vR, m, r);
update_vertex(v, l, r);
}
ll get_all() {
return tree[1].T;
}
};
void solve() {
int n, q;
cin >> n >> q >> s >> t;
vector<ll> a(n + 1);
for (auto &i: a) cin >> i;
SegTree tr(n + 1);
tr.build(a);
while (q--) {
int l, r;
ll x;
cin >> l >> r >> x;
tr.update_segment(l, r, x);
cout << tr.get_all() << en;
}
}
int main() {
#ifdef __APPLE__
freopen("input.txt", "r", stdin);
#else
ios_base::sync_with_stdio(0);
cin.tie(0);
#endif
solve();
return 0;
}
