dp 题，没有测试数据😭，应该是对的吧😋

#include <bits/stdc++.h>
using namespace std;
constexpr int inf = 0x3f3f3f3f;

void solve() {
    int n;
    cin >> n;
    vector a(n, 0);
    for (auto &i : a) {
        cin >> i;
    }
    vector dp(n, vector(3, inf));

    dp[0][0] = 1;
    if (a[0] == 3) {
        dp[0][1] = 0;
        dp[0][2] = 0;
    } else if (a[0] == 2) {
        dp[0][2] = 0;
    } else if (a[0] == 1) {
        dp[0][1] = 0;
    }

    auto _0 = [&](int i) {
        dp[i][0] = min(min(dp[i - 1][0], dp[i - 1][1]), dp[i - 1][2]) + 1;
    };

    auto _1 = [&](int i) {
        dp[i][1] = min(min(dp[i - 1][0], dp[i - 1][2]), dp[i - 1][1] + 1);
    };

    auto _2 = [&](int i) {
        dp[i][2] = min(min(dp[i - 1][0], dp[i - 1][1]), dp[i - 1][2] + 1);
    };


    for (int i = 1; i < n; ++i) {
        _0(i);
        if (a[i] == 3) {
            _1(i);
            _2(i);
        } else if (a[i] == 2) {
            _2(i);
        } else if (a[i] == 1) {
            _1(i);
        }
    }

    cout << min(min(dp[n - 1][0], dp[n - 1][1]), dp[n - 1][2]) << '\n';
}

int main() {
    int t;
    cin >> t;
    while (t--) solve();
    return 0;
}