Problem: 2060D - Subtract Min Sort
Language: java

Solution 1 (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();
		}
	}
}


Solution 2 (runtime: 499 ms):
import java.util.*;



public class Main {

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);

        int t = sc.nextInt(); // Number of test cases

        

        while (t-- > 0) {

            int n = sc.nextInt(); // Length of sequence

            int[] a = new int[n];

            

            for (int i = 0; i < n; i++) {

                a[i] = sc.nextInt();

            }



            // Simulating the operation

            boolean possible = true;

            for (int i = 0; i < n - 1; i++) {

                int minValue = Math.min(a[i], a[i + 1]);

                a[i] -= minValue;

                a[i + 1] -= minValue;

            }



            // Check if the array is now non-decreasing

            for (int i = 0; i < n - 1; i++) {

                if (a[i] > a[i + 1]) {

                    possible = false;

                    break;

                }

            }



            System.out.println(possible ? "YES" : "NO");

        }



        sc.close();

    }

}