#include <stdio.h>
#include <stdlib.h>
#include <set>
#include <map>
#include <list>
#include <queue>
#include <bitset>
#include <vector>
#include <climits>
#include <algorithm>
using namespace std;
#define int long long
#define uint unsigned int
#define inf ULLONG_MAX
const uint blksize = 2000;
struct block {
uint s;
int* a;
int v, pv;
};
int calc(uint blkc, struct block* blocks, uint S, uint T) {
#ifdef __DEBUG
for (uint x = 0; x < blkc; x++) {
printf("Block ID: %llu\n", x);
printf("\t%lld", blocks[x].a[0]);
for (uint i = 1; i < blocks[x].s; i++)
printf(" %lld", blocks[x].a[i]);
printf("\n");
printf("\tv = %lld, pv = %lld\n", blocks[x].v, blocks[x].pv);
}
#endif
int pv = blocks[0].pv;
for (uint b = 1; b < blkc; b++) {
pv += blocks[b].pv;
int r = blocks[b].a[0] + blocks[b].v,
l = blocks[b - 1].a[blocks[b - 1].s - 1] + blocks[b - 1].v;
if (r > l)
pv -= S * (r - l);
else
pv += T * (l - r);
}
return pv;
}
void update_block(struct block& block, uint S, uint T, uint l, uint r, int v) {
if (l == 0 && r == block.s - 1) {
block.v += v;
return;
}
if (l == 0)
block.a[l++] += v;
for (; l <= r; l++)
block.a[l] += v;
l = 1, block.pv = 0;
for (; l < block.s; l++) {
if (block.a[l] > block.a[l - 1])
block.pv -= S * (block.a[l] - block.a[l - 1]);
else
block.pv += T * (block.a[l - 1] - block.a[l]);
}
}
signed main() {
uint N, Q, S, T;
scanf("%llu%llu%llu%llu", &N, &Q, &S, &T);
const uint blkc = ((N + 1) / blksize) + ((N + 1) % blksize > 0);
struct block blocks[blkc];
uint n = N + 1;
for (uint x = 0; x < blkc; x++) {
blocks[x].s = min(blksize, n);
blocks[x].a = (int*)malloc(blocks[x].s * sizeof(int));
blocks[x].pv = 0, blocks[x].v = 0;
scanf("%lld", &blocks[x].a[0]);
for (uint i = 1; i < blocks[x].s; i++) {
scanf("%lld", &blocks[x].a[i]);
if (blocks[x].a[i] > blocks[x].a[i - 1])
blocks[x].pv -= (int)S * (blocks[x].a[i] - blocks[x].a[i - 1]);
else
blocks[x].pv += (int)T * (blocks[x].a[i - 1] - blocks[x].a[i]);
}
n -= min(blksize, n);
}
while (Q--) {
uint l, r; int v;
scanf("%llu%llu%lld", &l, &r, &v);
uint sbid = l / blksize;
uint ebid = r / blksize;
if (sbid == ebid)
update_block(blocks[sbid], S, T, l % blksize, r % blksize, v);
else {
update_block(blocks[sbid++], S, T, l % blksize, blksize - 1, v);
for (; sbid < ebid; sbid++)
update_block(blocks[sbid], S, T, 0, blksize - 1, v);
update_block(blocks[ebid], S, T, 0, r % blksize, v);
}
printf("%lld\n", calc(blkc, blocks, S, T));
}
}
