Problem: 2060D - Subtract Min Sort
Language: java

Solution 1 (runtime: 311 ms):
import java.io.*;
import java.util.*;

public class d {
	
	static BufferedReader br;
	static StringTokenizer st;
	static StringBuilder sb = new StringBuilder("");
	
	public static void main (String[] args) throws IOException {
		br = new BufferedReader(new InputStreamReader(System.in));
		st = new StringTokenizer(br.readLine());
		
		int t = Integer.parseInt(st.nextToken());
		
		for (int i = 0; i < t; i++) {
			st = new StringTokenizer(br.readLine());
			solve();
		}
		
		br.close();
		System.out.print(sb.toString());
	} 
 
	
	static void solve() throws IOException {
		int n = Integer.parseInt(st.nextToken());
		int[] A = new int[n+1];
		
		st = new StringTokenizer(br.readLine());
		
		for (int i = 1; i <= n; i++) {
			A[i] = Integer.parseInt(st.nextToken());
		}
		
		for (int i = 1; i <= n-1; i++) {
			int m = Math.min(A[i], A[i+1]);
			A[i] -= m;
			A[i+1] -= m;
		}
		
		
		for (int i = 1; i <= n-1; i++) {
			if (A[i] > A[i+1]) {
				sb.append("No\n");
				return;
			}
		}
		
		sb.append("Yes\n");
		
	}
	
	
	
}

Solution 2 (runtime: 375 ms):
import java.util.*;
import java.io.*;

public class Main {
	static InputStream inputStream;
	static OutputStream outputStream;
	static InputReader in;
	static PrintWriter out;
	static int MULTIPLE_TESTACES = 1;
  
	///////////////////////////////////////
	// solution
	///////////////////////////////////////
	static class Solution {
    
    private boolean pos(ArrayList<Long> o){
			int n = o.size();
			ArrayList<Long> a = new ArrayList<Long>();
			for(Long x: o){
				a.add(x);
			}
			for(int i=0; i<n-1;++i){
				long x = a.get(i);
				long y = a.get(i+1);
				long m = Math.min(x, y);
				a.set(i, x-m);
				a.set(i+1, y-m);
			}
			for(int i=0; i<n-1;++i){
				long x = a.get(i);
				long y = a.get(i+1);
				if(x > y)return false;
			}
			return true;
		}
		
		public void solve(int tc) throws IOException{
			int n = in.nextInt();
			ArrayList<Long> a = new ArrayList<Long>();
			for(int i=0; i<n;++i){
				a.add(in.nextLong());
			}
			boolean ans = false;
			ans |= pos(a);
			out.println(ans ? "YES":"NO");
		}	
	}
	
	
	
	
	
	///////////////////////////////////////
	// template
	///////////////////////////////////////
	public static void main(String[] args) throws IOException{
			inputStream = System.in;
			outputStream = System.out;
			in = new InputReader(inputStream);
			out = new PrintWriter(outputStream);
			int tc = 1;
			if(MULTIPLE_TESTACES>0)tc = in.nextInt();
			Solution sol = new Solution();
			for(int i=1; i<=tc;++i){
				 sol.solve(i);
			}
			in.close();
			out.close();
	}
	
	static class InputReader {
		BufferedReader reader;
		StringTokenizer st;
		public InputReader(InputStream in){
			reader = new BufferedReader(new InputStreamReader(in));
			st = null;
		}
		
		public String next() throws IOException{
			while(st == null || !st.hasMoreTokens()){
				st = new StringTokenizer(reader.readLine());
			}
			return st.nextToken();
		}
		
		public Long nextLong() throws IOException{
			return Long.parseLong(next());
		}
		
		public Integer nextInt() throws IOException{
			return Integer.parseInt(next());
		}
		
		public void close() throws IOException{
			reader.close();
		}
	}
}