#include<bits/stdc++.h>
using namespace std;
class segmentTree{
private:
int sze;
long long int upcost, downcost;
vector<long long int> tree;
vector<long long int> array;
void privUpdate(int pos, int val, int curpos, int curleft, int curright){
if(curleft==curright){
array[curleft]+=val;
if(array[curleft]>0){
tree[curpos]=array[curleft]*upcost;
}
else{
tree[curpos]=array[curleft]*downcost;
}
}
else{
int curmid = (curleft+curright)/2;
if(pos<=curmid){
privUpdate(pos, val, 2*curpos+1, curleft, curmid);
}
else{
privUpdate(pos, val, 2*curpos+2, curmid+1, curright);
}
tree[curpos]=tree[2*curpos+1]+tree[2*curpos+2];
}
}
long long int privGetSum(int qleft, int qright, int nodepos, int nodeleft, int noderight){
if(qright<nodeleft || qleft>=noderight){
return 0;
}
else if(qleft<=nodeleft && noderight<=qright){
return tree[nodepos];
}
else{
int nodemid = (nodeleft+noderight)/2;
return privGetSum(qleft, qright, 2*nodepos+1, nodeleft, nodemid)+privGetSum(qleft, qright, 2*nodepos+2, nodemid+1, noderight);
}
}
public:
segmentTree(vector<long long int> vect, long long int _upcost, long long int _downcost): upcost(_upcost), downcost(_downcost), sze(vect.size()){
array.resize(sze);
tree.resize(4*sze, 0);
privUpdate(0, 0, 0, 0, sze-1);
for(int i=1; i<vect.size(); i++){
privUpdate(i, vect[i]-vect[i-1], 0, 0, sze-1);
}
}
long long int query(int left, int right, long long int val){
privUpdate(left, val, 0, 0, sze-1);
if(right!=sze-1){
privUpdate(right+1, 0-val, 0, 0, sze-1);
}
return privGetSum(0, sze-1, 0, 0, sze-1);
}
};
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n, q;
long long int s, t;
cin >> n >> q >> s >> t;
vector<long long int> vect(n+1);
for(int i=0; i<=n; i++){
cin >> vect[i];
}
segmentTree tree(vect, 0-s, 0-t);
for(int i=0; i<q; i++){
int a, b;
long long int c;
cin >> a >> b >> c;
cout << tree.query(a, b, c) << '\n';
}
return 0;
}
