public static void main ( String [ ] args ) throws Exception {
  String yes = "YES" ;
  String no = "NO" ;
  Scanner sc = new Scanner ( System . in ) ;
  int t = sc . nextInt ( ) ;
  for ( int i = 0 ;
  i < t ;
  i ++ ) {
    int n = sc . nextInt ( ) ;
    int [ ] nums = new int [ n ] ;
    int max = 0 ;
    for ( int j = 0 ;
    j < n ;
    j ++ ) {
      nums [ j ] = sc . nextInt ( ) ;
      if ( j > 0 ) {
        max += Math . max ( 0 , nums [ j - 1 ] - nums [ j ] ) ;
      }
    }
    System . out . println ( ( max <= nums [ 0 ] ) ? yes : no ) ;
  }
}

public static void main ( String [ ] args ) throws Exception { String yes = " YES " ; String no = " NO " ; Scanner sc = new Scanner ( System . in ) ; int t = sc . nextInt ( ) ; for ( int i = 0 ; i < t ; i ++ ) { int n = sc . nextInt ( ) ; int [ ] nums = new int [ n ] ; int max = 0 ; for ( int j = 0 ; j < n ; j ++ ) { nums [ j ] = sc . nextInt ( ) ; if ( j > 0 ) { max += Math . max ( 0 , nums [ j - 1 ] - nums [ j ] ) ; } } System . out . println ( ( max <= nums [ 0 ] ) ? yes : no ) ; } }
(method_declaration (modifiers) type: (void_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (array_type element: (type_identifier) dimensions: (dimensions)) name: (identifier))) (throws (type_identifier)) body: (block (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (string_literal))) (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (string_literal))) (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (type_identifier) arguments: (argument_list (field_access object: (identifier) field: (identifier)))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (local_variable_declaration type: (array_type element: (integral_type) dimensions: (dimensions)) declarator: (variable_declarator name: (identifier) value: (array_creation_expression type: (integral_type) dimensions: (dimensions_expr (identifier))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (block (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) consequence: (block (expression_statement (assignment_expression left: (identifier) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (decimal_integer_literal) (binary_expression left: (array_access array: (identifier) index: (binary_expression left: (identifier) right: (decimal_integer_literal))) right: (array_access array: (identifier) index: (identifier))))))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (ternary_expression condition: (parenthesized_expression (binary_expression left: (identifier) right: (array_access array: (identifier) index: (decimal_integer_literal)))) consequence: (identifier) alternative: (identifier)))))))))