public static void main ( String [ ] args ) {
  Scanner sc = new Scanner ( System . in ) ;
  int t = sc . nextInt ( ) ;
  while ( t -- > 0 ) {
    int n = sc . nextInt ( ) ;
    int q = sc . nextInt ( ) ;
    String s = sc . next ( ) ;
    while ( q -- > 0 ) {
      int l = sc . nextInt ( ) ;
      int r = sc . nextInt ( ) ;
      String st = s . substring ( l - 1 , r ) ;
      int c = l - 1 ;
      int lis = 0 , ini = 0 ;
      for ( int i = 0 ;
      i < s . length ( ) ;
      i ++ ) {
        char ch = s . charAt ( i ) ;
        if ( s . charAt ( c ) == ch ) {
          if ( c == l - 1 ) ini = i ;
          else lis = i ;
          if ( c != r - 1 ) c ++ ;
        }
      }
      if ( ini == l - 1 && lis == r - 1 ) System . out . println ( "NO" ) ;
      else System . out . println ( "YES" ) ;
    }
  }
}

public static void main ( String [ ] args ) { Scanner sc = new Scanner ( System . in ) ; int t = sc . nextInt ( ) ; while ( t -- > 0 ) { int n = sc . nextInt ( ) ; int q = sc . nextInt ( ) ; String s = sc . next ( ) ; while ( q -- > 0 ) { int l = sc . nextInt ( ) ; int r = sc . nextInt ( ) ; String st = s . substring ( l - 1 , r ) ; int c = l - 1 ; int lis = 0 , ini = 0 ; for ( int i = 0 ; i < s . length ( ) ; i ++ ) { char ch = s . charAt ( i ) ; if ( s . charAt ( c ) == ch ) { if ( c == l - 1 ) ini = i ; else lis = i ; if ( c != r - 1 ) c ++ ; } } if ( ini == l - 1 && lis == r - 1 ) System . out . println ( " NO " ) ; else System . out . println ( " YES " ) ; } } }
(method_declaration (modifiers) type: (void_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (array_type element: (type_identifier) dimensions: (dimensions)) name: (identifier))) body: (block (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)))) (while_statement condition: (parenthesized_expression (binary_expression left: (update_expression (identifier)) right: (decimal_integer_literal))) 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: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (while_statement condition: (parenthesized_expression (binary_expression left: (update_expression (identifier)) right: (decimal_integer_literal))) 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: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (binary_expression left: (identifier) right: (decimal_integer_literal)) (identifier))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (binary_expression left: (identifier) right: (decimal_integer_literal)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal)) 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: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))) 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 (identifier))))) (if_statement condition: (parenthesized_expression (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))) right: (identifier))) consequence: (block (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (binary_expression left: (identifier) right: (decimal_integer_literal)))) consequence: (expression_statement (assignment_expression left: (identifier) right: (identifier))) alternative: (expression_statement (assignment_expression left: (identifier) right: (identifier)))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (binary_expression left: (identifier) right: (decimal_integer_literal)))) consequence: (expression_statement (update_expression (identifier)))))))) (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (identifier) right: (binary_expression left: (identifier) right: (decimal_integer_literal))) right: (binary_expression left: (identifier) right: (binary_expression left: (identifier) right: (decimal_integer_literal))))) consequence: (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (string_literal)))) alternative: (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (string_literal)))))))))))