#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define db double
#define in inline
const int N = 2e5+10,M = N<<3;
const ll inf = 1e17;
 
 
ll read(){
    ll x = 0,f = 1;char c = getchar();
    for(;c < '0' || c > '9';c = getchar())if(c == '-')f = -1;
    for(;c >= '0' && c <= '9';c = getchar())x = (x<<1) + (x<<3) + c-'0';
    return x * f;
}
 
int n,m;
ll a[N],S,T;
 
struct segment{
    ll s[M],lm[M],rm[M],la[M];
    void pushup(int p){
        lm[p] = lm[p<<1],rm[p] = rm[p<<1|1];
        s[p] = s[p<<1] + s[p<<1|1];
        int ls = rm[p<<1],rs = lm[p<<1|1];
        if(ls > rs)s[p] += T * (ls - rs);
        else if(rs > ls)s[p] -= S * (rs - ls);
    }
    void pushdown(int p){
        lm[p<<1] += la[p],lm[p<<1|1] += la[p];
        rm[p<<1] += la[p],rm[p<<1|1] += la[p];
        la[p<<1] += la[p],la[p<<1|1] += la[p];
        la[p] = 0;
    }
    void build(int p,int l,int r){
        if(l == r)return lm[p] = rm[p] = a[l],void();
        int mid = l + r >> 1;
        build(p<<1,l,mid),build(p<<1|1,mid+1,r);
        pushup(p);
    }
    void modify(int p,int l,int r,int L,int R,ll z){
        if(L <= l && r <= R)return la[p] += z,lm[p] += z,rm[p] += z,void();
        int mid = l + r >> 1;
        pushdown(p);
        if(L <= mid)modify(p<<1,l,mid,L,R,z);
        if(R > mid)modify(p<<1|1,mid+1,r,L,R,z);
        pushup(p);
    }
}t;
 
ll ans = 0;
int main(){
    freopen("foehn-13.in","r",stdin);
    freopen("foehn.out","w",stdout);
    n = read() + 1,m = read(),S = read(),T = read();
    for(int i = 1;i <= n;i++)a[i] = read();
    t.build(1,1,n);
    for(int i = 1;i <= m;i++){
        int l = read()+1,r = read()+1;ll z = read();
        t.modify(1,1,n,l,r,z);
        printf("%lld\n",t.s[1]);
    }
    
    return 0;
    
}