// #define _GLIBCXX_DEBUG #include #include #define rep(i,b) for(int i=0;i=0;i--) #define rep1(i,b) for(int i=1;i=x;i--) #define fore(i,a) for(auto i:a) #define fore1(i,a) for(auto &i:a) #define rng(x) (x).begin(), (x).end() #define rrng(x) (x).rbegin(), (x).rend() #define sz(x) ((int)(x).size()) #define pb push_back #define fi first #define se second using namespace std; using namespace atcoder; using ll = long long; template using mpq = priority_queue, greater>; template bool chmax(T &a, const T &b) { if (a bool chmin(T &a, const T &b) { if (b ll sumv(const vector&a){ll res(0);for(auto&&x:a)res+=x;return res;} bool yn(bool a) { if(a) {cout << "Yes" << endl; return 1;} else {cout << "No" << endl; return 0;}} #define dame { cout << "No" << endl; return 0;} #define dame1 { cout << -1 << endl; return 0;} #define test(x) cout << "test" << x << endl; #define deb(x,y) cout << x << " " << y << endl; #define debp(p) cout << p.fi << " " << p.se << endl; #define deb3(x,y,z) cout << x << " " << y << " " << z << endl; #define deb4(x,y,z,x2) cout << x << " " << y << " " << z << " " << x2 << endl; #define out cout << ans << endl; #define outv fore(yans , ans) cout << yans << "\n"; #define show(x) cerr<<#x<<" = "<; using pil = pair; using pli = pair; using pii = pair; using tp = tuple; using vi = vector; using vl = vector; using vs = vector; using vb = vector; using vpii = vector; using vpli = vector; using vpll = vector; using vpil = vector; using vvi = vector>; using vvl = vector>; using vvs = vector>; using vvb = vector>; using vvpii = vector>; using vvpli = vector>; using vvpll = vector; using vvpil = vector; using mint = modint998244353; using vm = vector; using vvm = vector>; vector dx={1,0,-1,0,1,1,-1,-1},dy={0,1,0,-1,1,-1,1,-1}; ll gcd(ll a, ll b) { return a?gcd(b%a,a):b;} ll lcm(ll a, ll b) { return a/gcd(a,b)*b;} const double eps = 1e-10; const ll LINF = 1001002003004005006ll; const int INF = 1001001001; int main(){ int t; cin>>t; vs ans(t); rep(j,t){ ll n,m; cin>>n>>m; vl a(n),b(n); rep(i,n) cin>>a[i]; ll now = m; bool ok = true; rep(i,n-1){ ll tmp = (a[i] - b[i]); now -= tmp; b[i+1] += now; if (tmp < 0) ok = false; if (now < 0) ok = false; // if (j == 0) deb(tmp , now); now = a[i]; // if (j == 0) show(i); // if (j == 0) deb(a[i] , b[i]); } // showv(b); if (b[n-1]+now != a[n-1]) ok = false; if (ok) ans[j] = "Yes"; else ans[j] = "No"; } outv; // 消せ!!!!!! #define _GLIBCXX_DEBUG // priority_queue でしぬ return 0; }