差分20pts求调，似乎不是没清空的问题

除样例、#1、#2正确外，其它全部WA。

#include<bits/stdc++.h>
#define int long long
using namespace std;
const int MAXN = 2e5 + 5;
struct node
{
    int l, r;
};
node s[MAXN];
int a[MAXN];
int b[MAXN];
int t;
int n, m, k, p;
int minn;
priority_queue<int> pq;
bool check(int x)
{
    while(!pq.empty())
    {
        pq.pop();
    }
    int sum = 0;
    int tot = 0;
    memset(b, 0, sizeof(b));
    int cur = 1;
    for(int i = 1; i <= n; i ++)
    {
        sum += b[i];
        int temp = a[i] + sum;
        if(temp < x)
        {
            while(!pq.empty() && pq.top() < i)
            {
                pq.pop();
            }
            while(cur <= m && s[cur].l <= i)
            {
                if(s[cur].l >= i)
                {
                    pq.push(s[cur].r);
                }
                cur ++;
            }
            int cnt = (x - temp) / p;
            if((x - temp) % p)
            {
                cnt ++;
            }
            if(tot + cnt > k)
            {
                return false;
            }
            tot += cnt;
            for(int j = 1; j <= cnt; j ++)
            {
                if(!pq.empty() && pq.top() >= i)
                {
                    sum += p;
                    b[pq.top() + 1] -= p;
                    pq.pop();
                }
                else
                {
                    return false;
                }
            }
        }
    }
    return true;
}
int dich()
{
    int l = minn - 1;
    int r = minn + k * p + 1;
    while(l + 1 < r)
    {
        int mid = (l + r) / 2;
        if(check(mid) == true)
        {
            l = mid;
        }
        else
        {
            r = mid;
        }
    }
    return l;
}
bool cmp(node x, node y)
{
    if(x.l != y.l)
    {
        return x.l < y.l;
    }
    return x.r > y.r;
}
signed main()
{
    cin >> t;
    while(t --)
    {
        cin >> n >> m >> k >> p;
        minn = 1e9;
        for(int i = 1; i <= n; i ++)
        {
            cin >> a[i];
            minn = min(minn, a[i]);
        }
        for(int i = 1; i <= m; i ++)
        {
            cin >> s[i].l >> s[i].r;
        }
        sort(s + 1, s + m + 1, cmp);
        cout << dich() << endl;
    }
    return 0;
}
```。