40分求助

样例正确，神犇们快帮帮蒟蒻吧！ （前四个点AC，5，6WA，7，8，9，10TLE）

    #include <bits/stdc++.h>
    using namespace std;
    int n, j, q, l, e, o = -1;
    int a[10000005], yu[10] = {1, 10, 100, 1000, 10000, 100000, 1000000, 10000000,100000000,1000000000};
    int main() {
        cin >> n >> q;
        for (int i = 1; i <= n; i++) {
            cin >> a[i];
        }
        sort(a, a + n);
        j = q;
        while (j != 0) {
            j--;
            cin >> l >> n;
            o = -1;
            for (int i = 1; i <= n; i++) {
                e = a[i] % yu[l];
                if (e == n) {
                    o = a[i];
                    break;
                }
            }
            cout << o << endl;
        }
        system ("pause");
    }