#include <bits/stdc++.h>
#define all(v) begin(v), end(v)
#define ii pair<int, int>
#define fi first
#define se second
#define siz(v) (int)(v).size()
#define lli pair<long long, int>
#define dbg(x) "[" #x " = " << x << "]"
#define BIT(x, i) (((x) >> (i)) & 1)
#define MASK(i) (1LL << (i))
using namespace std;
const int mod = 1e9 + 7, infINT = 1e9 + 1321;
template<class X, class Y> bool minimize(X &x, const Y &y){return x > y ? x = y, 1: 0;}
template<class X, class Y> bool maximize(X &x, const Y &y){return x < y ? x = y, 1: 0;}
struct fenwickTree{
int n;
vector<long long > bit;
fenwickTree(int _n = 0): n(_n){
bit.assign(n + 1, 0);
}
void update(int pos, const long long &delta){
for(; pos <= n; pos += pos & -pos) bit[pos] += delta;
}
void update(int l, int r, const long long &delta){
update(l, +delta);
update(r + 1, -delta);
}
long long get(int pos){
long long sum = 0;
for(; pos > 0; pos ^= pos & -pos) sum += bit[pos];
return sum;
}
};
const int MAXN = 1e6 + 6;
int numVal, numQuery, up, down, val[MAXN];
long long diff[MAXN];
void input(){
cin >> numVal >> numQuery >> up >> down;
++numVal;
for(int i = 1; i <= numVal; i++) cin >> val[i];
}
long long sum;
void update(const int &pos, const int &change){
if (diff[pos] < 0) sum += 1LL * change * 1LL * up * 1LL * diff[pos];
else sum += 1LL * change * 1LL * down * 1LL * diff[pos];
}
void solve(){
for(int i = 2; i <= numVal; i++){
diff[i] = val[i - 1] - val[i];
update(i, +1);
}
fenwickTree bit(numVal);
for(int i = 1; i <= numVal; i++){
bit.update(i, i, +val[i]);
}
for(int q = 1; q <= numQuery; q++){
int L, R, delta; cin >> L >> R >> delta;
L++; R++;
if (L > 1){
update(L, -1);
}
if (R < numVal){
update(R + 1, -1);
}
bit.update(L, R, +delta);
if (L > 1){
diff[L] = bit.get(L - 1) - bit.get(L);
update(L, +1);
}
if (R < numVal){
diff[R + 1] = bit.get(R) - bit.get(R + 1);
update(R + 1, +1);
}
cout << sum << '\n';
}
}
signed main(){
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define task "test"
if (fopen(task".inp", "r")){
freopen(task".inp", "r", stdin);
freopen(task".out", "w", stdout);
}
input();
solve();
cerr << (1.0 * clock()) / CLOCKS_PER_SEC << ".s\n";
}
