http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemCode=4094

题解：

1、向上依次寻找可代替药水；

2、如果当前不能满足则找不到；

/*
*@Author:   STZG
*@Language: C++
*/
#include <bits/stdc++.h>
#include<iostream>
#include<algorithm>
#include<cstdlib>
#include<cstring>
#include<cstdio>
#include<string>
#include<vector>
#include<bitset>
#include<queue>
#include<deque>
#include<stack>
#include<cmath>
#include<list>
#include<map>
#include<set>
//#define DEBUG
#define RI register int
#define endl "\n"
using namespace std;
typedef long long ll;
//typedef __int128 lll;
const int N=100000+10;
const int M=100000+10;
const int MOD=1e9+7;
const double PI = acos(-1.0);
const double EXP = 1E-8;
const int INF = 0x3f3f3f3f;
int t,n,m,k,p,l,r,u,v;
int ans,cnt,flag,temp,sum;
int a[N],b[N];
char str;
struct node{};
int main()
{
#ifdef DEBUG
	freopen("input.in", "r", stdin);
	//freopen("output.out", "w", stdout);
#endif
    //ios::sync_with_stdio(false);
    //cin.tie(0);
    //cout.tie(0);
    scanf("%d",&t);
    while(t--){
        scanf("%d",&n);
        for(int i=1;i<=n;i++){
            scanf("%d",&a[i]);
        }
        for(int i=1;i<=n;i++){
            scanf("%d",&b[i]);
        }
        ans=1;
        for(int i=1;i<=n;i++){
            for(int j=i;j<=n;j++){
                if(a[i]>b[j]){
                    a[i]=a[i]-b[j];
                    b[j]=0;
                }else{
                    b[j]=b[j]-a[i];
                    a[i]=0;
                    break;
                }
                if(j==n){
                    ans=0;
                }
            }//cout<<a[i]<<endl;
        }
        cout<<(ans?"Yes":"No")<<endl;
    }
 
#ifdef DEBUG
	printf("Time cost : %lf s\n",(double)clock()/CLOCKS_PER_SEC);
#endif
    //cout << "Hello world!" << endl;
    return 0;
}