#include <cstdio>
#include <cstring>
#include <algorithm>
#include <vector>
#include <iostream>
#include <cassert>
#include <cmath>
#include <string>
#include <queue>
#include <set>
#include <map>
#include <cstdlib>
using namespace std;
#define INF 1e+9
#define mp make_pair
#define pb push_back
#define fi first
#define fs first
#define se second
#define i64 long long
#define li long long
#define lint long long
#define pii pair<int, int>
#define vi vector<int>
#define forn(i, n) for (int i = 0; i < (int)n; i++)
#define fore(i, b, e) for (int i = (int)b; i <= (int)e; i++)
const int maxn = 2e5+5;
i64 tree[maxn * 4];
int start[maxn];
i64 S, T;
int n;
i64 get(int i, int L, int R, int pos) {
if (L + 1 == R)
return tree[i];
int M = (L + R) / 2;
return (pos < M ? get(i * 2, L, M, pos) : get(i * 2 + 1, M, R, pos)) + tree[i];
}
i64 get(int pos) {
return get(1, 0, n + 1, pos);
}
void upd(int i, int L, int R, int A, int B, int diff) {
if (L >= B || A >= R)
return;
if (L >= A && R <= B) {
tree[i] += diff;
return;
}
int M = (L + R) / 2;
upd(i * 2, L, M, A, B, diff);
upd(i * 2 + 1, M, R, A, B, diff);
}
void build(int i, int L, int R) {
if (L + 1 == R) {
tree[i] = start[L];
return;
}
int M = (L + R) / 2;
build(i * 2, L, M);
build(i * 2 + 1, M, R);
}
i64 calc(i64 fi, i64 se) {
return se > fi ? (se - fi) * -S : (fi - se) * T;
}
int main() {
#ifdef LOCAL
freopen("inp", "r", stdin);
//freopen("outp", "w", stdout);
#else
// freopen(TASKNAME ".in", "r", stdin);
// freopen(TASKNAME ".out", "w", stdout);
#endif
int Q;
cin >> n >> Q >> S >> T;
forn(i, n + 1) {
scanf("%d", &start[i]);
}
build(1, 0, n + 1);
i64 ans = 0;
forn(i, n)
ans += calc(start[i], start[i + 1]);
forn(q, Q) {
int L, R, diff;
scanf("%d%d%d", &L, &R, &diff);
ans -= calc(get(L - 1), get(L));
if (R != n)
ans -= calc(get(R), get(R + 1));
upd(1, 0, n + 1, L, R + 1, diff);
ans += calc(get(L - 1), get(L));
if (R != n)
ans += calc(get(R), get(R + 1));
cout << ans << endl;
}
}
