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#include <bits/stdc++.h>
#define FOR(i, a, b) for (int i = (a); i <= (b); ++i)
#define ROF(i, a, b) for (int i = (a); i >= (b); --i)
#define all(x) x.begin(), x.end()
#define CLR(i, a) memset(i, a, sizeof(i))
#define fi first
#define se second
#define pb push_back
#define SZ(a) ((int)a.size())
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll, ll> pll;
typedef array<ll, 3> arr;
typedef double DB;
typedef pair<DB, DB> pdd;
constexpr ll MAXN = static_cast<ll>(2e5) + 10, INF = static_cast<ll>(5e18) + 3;
ll N, T, A[MAXN], backup[MAXN];
inline void solve() {
cin >> N;
FOR(i, 1, N) { cin >> A[i]; }
if (A[1] > A[2]) {
cout << "NO\n";
return;
}
FOR(i, 1, N - 1) {
ll t1 = A[i] - min(A[i], A[i + 1]), t2 = A[i + 1] - min(A[i], A[i + 1]);
A[i] = t1;
A[i + 1] = t2;
}
FOR(i, 1, N) { backup[i] = A[i]; }
sort(A + 1, A + 1 + N);
FOR(i, 1, N) {
if (backup[i] != A[i]) {
cout << "NO\n";
return;
}
}
cout << "YES\n";
}
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
cin >> T;
while (T--) {
solve();
}
return 0;
}
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