Code: Lost Civilization (Easy Version)

#include <bits/stdc++.h>

using i64 = long long;
using u64 = unsigned long long;
using u32 = unsigned;

using u128 = unsigned __int128;
using i128 = __int128;

void solve() {
    int n;
    std::cin >> n;

    std::vector<int> a(n);
    for (int i = 0; i < n; i++) {
        std::cin >> a[i];
    }

    std::vector<int> stk;
    for (int i = n - 1; i >= 0; i--) {
        while (!stk.empty() && stk.back() == a[i] + 1) {
            stk.pop_back();
        }
        stk.push_back(a[i]);
    }

    std::cout << stk.size() << "\n";
}

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);

    int t;
    std::cin >> t;

    while (t--) {
        solve();
    }

    return 0;
}