1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
#include <algorithm>
#include <cstdio>

#define REP(a, n) for (int a = 0; a<(n); ++a)
#define FOR(a, b, c) for (int a = (b); a<=(c); ++a)

typedef long long LL;

using namespace std;

//////////////

bool ok_tu(LL cel, LL W, LL T, LL D) {
    W = min(W, 200'000LL);
    T = min(T, 200LL);
    D = min(D, 200'000LL);
    LL ile = T*(T-1)*(T-2)/6+W*T*D+W*T*(T-1)/2+T*(T-1)/2*D;
    return ile>=cel;
}

int N;

int tab[200000];

bool ok(LL Z) {
    LL W = 0;
    REP(a, N) {
        LL L = -1, R = Z+1;
        while (R-L>1) {
            LL M = (L+R)/2;
            (ok_tu(tab[a], W, M, Z-M) ? R : L) = M;
        }
        if (R>Z)
            return 0;
        W += R;
        Z -= R;
    }
    return 1;
}

void licz() {
    scanf("%d", &N);
    REP(a, N)
        scanf("%d", &tab[a]);
    LL L = 0, R = 200'000*200;
    while (R-L>1) {
        LL M = (L+R)/2;
        (ok(M) ? R : L) = M;
    }
    printf("%lld\n", R);
}

int main() {
    int T;
    scanf("%d", &T);
    REP(tt, T)
        licz();
}