#pragma GCC optimize("O3")
#include <bits/stdc++.h>
#define ll long long
#define str string
#define pb push_back
#define pf push_front
#define in insert
#define all(v) v.begin(),v.end()
const int sz=1000000,INF=1000000000;
using namespace std;
ll f(ll num1,ll num2,vector<ll>nums)
{
ll res=0;
for(int i=0;i<nums.size()-1;i++)
{
if(nums[i]<nums[i+1])
{
res-=abs(nums[i]-nums[i+1])*num1;
}
else
{
res+=abs(nums[i]-nums[i+1])*num2;
}
}
return res;
}
void solve()
{
ll n,m,l,p,num,num1,num2,num3,ans;
cin>>n>>m>>l>>p;
vector<ll>nums;
for(int i=0;i<n+1;i++)
{
cin>>num;
nums.pb(num);
}
for(int i=0;i<m;i++)
{
cin>>num1>>num2>>num3;
for(int j=num1;j<=num2;j++)
{
nums[j]+=num3;
}
ans=f(l,p,nums);
cout<<ans<<"\n";
}
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr),cout.tie(nullptr);
ll t=1;
//cin>>t;
while(t--)
{
solve();
}
}
