maximum_difference

#include <bits/stdc++.h>

using namespace std;

void solve();
int maximum_length(int N, vector<int> &Y);

int query(vector<int> &tree, int v, int tl, int tr, int l, int r);
void update(vector<int> &tree, int v, int tl, int tr, int pos, int new_val);

int main() {
    int t = 1;
    scanf("%d", &t);
    while (t--) solve();
    return 0;
}
void solve() {
    int n, i, j;
    scanf("%d", &n);
    vector<int> arr(n);
    for (i = 0; i < n; ++i) scanf("%d", &arr[i]);
    printf("%d\n", maximum_length(n, arr));
}
int maximum_length(int N, vector<int> &Y) {
    vector<pair<int, int>> temp;
    int i;
    for (i = 0; i < N; ++i) temp.push_back({Y[i], i});
    sort(temp.begin(), temp.end());

    vector<int> indices(N), val(N);
    for (i = 0; i < N; ++i) {
        val[i] = temp[i].first;
        indices[i] = temp[i].second;
    }
    int ans = 0;
    vector<int> tree(4 * N);
    for (i = 0; i < N; ++i) {
        update(tree, 1, 1, 2 * N, i + 1, indices[i]);
    }

    for (i = 0; i < N; ++i) {
        int ind = lower_bound(val.begin(), val.end(), Y[i]) - val.begin();
        if (ind != 0) {
            int idx = query(tree, 1, 1, 2 * N, 1, ind);
            ans = max(ans, i - idx);
        }
    }
    return ans;
}

int query(vector<int> &tree, int v, int tl, int tr, int l, int r) {
    if (l > r)
        return INT32_MAX;
    if (l == tl && r == tr)
        return tree[v];
    int tm = (tl + tr) / 2;
    return min(query(tree, 2 * v, tl, tm, l, min(r, tm)), query(tree, 2 * v + 1, tm + 1, tr, max(l, tm + 1), r));
}
void update(vector<int> &tree, int v, int tl, int tr, int pos, int new_val) {
    if (tl == tr)
        tree[v] = new_val;
    else {
        int tm = (tl + tr) / 2;
        if (pos <= tm)
            update(tree, 2 * v, tl, tm, pos, new_val);
        else
            update(tree, 2 * v + 1, tm + 1, tr, pos, new_val);
        tree[v] = min(tree[2 * v], tree[2 * v + 1]);
    }
}