func_code_string: #include <bits/stdc++.h>   using namespace std;   const double eps = 1e-8;   const int mod = 1e9 + 7;   const int N = 1e6 + 10;   const int inf = 1e9;   int t, n, a[N], b[N];   int gao(int x) {     int res = b[1] - x;     for (int i = 2; i <= n; i++) {       res = b[i] - max(a[i] - res, 0);       if (res < 0) return -1;     }     return res;   }   int main() {     ios::sync_with_stdio(false);     cin >> t;     while (t--) {       cin >> n;       for (int i = 1; i <= n; i++) cin >> a[i];       for (int i = 1; i <= n; i++) cin >> b[i];       int l = 0, r = b[1], ans = 0;       while (l <= r) {         int mid = l + r >> 1;         int ret = gao(mid);         if (ret == -1) {           r = mid - 1;         } else           l = mid + 1;         if (ret != -1 && ret + mid >= a[1]) {           ans = 1;         }       }       if (ans)         puts( YES );       else         puts( NO );     }     return 0;   }   