#include using namespace std; using ll = long long; using pii = pair; using vpii = vector; using vi = vector; using vll = vector; using mpii = map; using mpll = map; using db = long double; #define pb push_back #define all(x) (x).begin(), (x).end() #define rall(x) (x).rbegin(), (x).rend() #define lb lower_bound #define ub upper_bound #define make_unique(x) \ sort(all((x))); \ (x).resize(unique(all((x))) - (x).begin()) #define ceil(a, b) ((a) + (b)-1) / (b) const int mod = (int)1e9 + 7; const db pi = acos((db)-1); const int dx[4]{1, 0, -1, 0}; const int dy[4]{0, 1, 0, -1}; #ifdef LOCAL #include "debug.h" #else #define dbg(...) 42 #endif /* stuff you should look for: --------------------------- * special cases (n=1?) * int overflow, array bounds * do smth instead of nothing and stay organized * WRITE STUFF DOWN * DON'T GET STUCK ON ONE APPROACH */ void apply(vi &v, int idx, int times) { v[idx] -= 2 * times; v[idx - 1] -= times; v[idx + 1] -= times; } void solve() { int n; cin >> n; vi v(n); for (auto &x : v) { cin >> x; } for (int i = 0; i < n - 2; i++) { int times = v[i]; if (times < 0) { cout << "NO\n"; return; } apply(v, i + 1, times); } if (all_of(all(v), [](int x) { return x == 0; })) { cout << "YES\n"; } else { cout << "NO\n"; } } int main() { ios_base::sync_with_stdio(false); cin.tie(NULL); int tt; cin >> tt; while (tt--) { solve(); } }