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: 312 ms):
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class prob {

    static class FastReader {
        BufferedReader b;
        StringTokenizer s;

        public FastReader() {
            b = new BufferedReader(new InputStreamReader(System.in));
        }

        String next() {
            while (s == null || !s.hasMoreElements()) {
                try {
                    s = new StringTokenizer(b.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return s.nextToken();
        }

        int nextInt() {
            return Integer.parseInt(next());
        }

        long nextLong() {
            return Long.parseLong(next());
        }

        double nextDouble() {
            return Double.parseDouble(next());
        }

        float nextFloat() {
            return Float.parseFloat(next());
        }

        boolean nextBoolean() {
            return Boolean.parseBoolean(next());
        }

        // Method to read the next line as a string
        String nextLine() {
            String str = "";
            try {
                if (s == null || !s.hasMoreTokens()) {
                    str = b.readLine();
                } else {
                    str = s.nextToken("\n");
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
    }

    //===================================================================================================

    public static void main(String[] args) {
        FastReader fastReader = new FastReader();

        int t=0;
        t = fastReader.nextInt();

        while(t-- >0){
            int n = fastReader.nextInt();
            int[] arr = new int[n];

            for(int i=0;i<n;i++){
                arr[i] = fastReader.nextInt();
            }

            solve(arr, n);
        }
    }

    public static void solve(int[] arr, int n){

        for(int i=0;i<n-1;i++){
            int var = Math.min(arr[i], arr[i+1]);
            arr[i]-=var;
            arr[i+1]-=var;
        }

        for(int i=0;i<n-1;i++){
            if(arr[i+1]<arr[i]){
                System.out.println("NO");
                return;
            }
        }

        System.out.println("YES");
    }
}