根据题意进行二分查找即可。

参考代码(C++)：

#include <bits/stdc++.h>
using namespace std;

#define debug(x) cerr << #x" = " << x << " ";
#define dbged cerr << "\n";

using ll = long long;
using ull = unsigned long long;
using PII = pair<int, int>;

signed main() {

    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    int n;
    cin >> n;
    vector<int> a(n + 1);
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
    }
    
    int t;
    cin >> t;
    while (t--) {
        double p, q;
        int l, r, y;
        cin >> p >> q >> l >> r >> y;
        
        int lo = l - 1, hi = r + 1;
        while (lo + 1 < hi) {
            int mid = lo + ((hi - lo) >> 1);
            int res = p * a[mid] + q;
            if (res <= y) {
                lo = mid;
            } else {
                hi = mid;
            }
        }
        
        if (lo < l) {
            cout << "-1\n";
        } else {
            cout << lo << "\n";
        }
    }

    return 0;
}