Input file: | Standard input | Time limit: | 5 sec | |
Output file: | Standard output | Memory limit: | 512 Mb |
Let the assignment expression be described by the following grammar
Comma = ",", { " " };
Digit = "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9";
Number = "0" | ( Digit, { Digit | "0" } );
Letter = "A" | "B" | "C" | "D" | "E" | "F" | "G"
| "H" | "I" | "J" | "K" | "L" | "M" | "N"
| "O" | "P" | "Q" | "R" | "S" | "T" | "U"
| "V" | "W" | "X" | "Y" | "Z" | "a" | "b"
| "c" | "d" | "e" | "f" | "g" | "h" | "i"
| "j" | "k" | "l" | "m" | "n" | "o" | "p"
| "q" | "r" | "s" | "t" | "u" | "v" | "w"
| "x" | "y" | "z" ;
Variable = Letter, { Letter | Digit | "0" };
Value = Variable | Number | EnclosedValueList | EmptyList;
ValueList = Value, { Comma, Value }, [ Comma ];
EnclosedValueList = "(", ValueList , ")";
EmptyList = "(", { " " }, ")";
Destination = Variable | EnclosedDestinationList;
DestinationList = Destination, { Comma, Destination }, ( [ Comma, "*", Variable ] | [ Comma ] );
EnclosedDestinationList = "(", DestinationList, ")";
Assignment = ( DestinationList | EnclosedDestinationList ), " = ", ( ValueList | EnclosedValueList );
Both sides are treated as potentially nested lists. A variable on the left side is assigned a value placed at the same position on the right side. A value therefore may be a Number, a Variable or a list. A list must be enclosed in parenthesis and have at least one comma, i.e. (a,)
is a list and (a)
is equivalent to simply a
. Additionally, parenthesis at the top level may be omitted. The assignment is performed from top to bottom, left to right, meaning that a Variable may be used as Value on the right side if it has already been assigned a Value. In a special case that a Variable is preceded by an asterisk it is assigned a potentially empty list of the rest of the Values at that level. The assignment fails if a Variable or a Value doesn't have a corresponding item on the other side or if a Variable is used as a Value before it has been assigned a Value.
Your program must decompose such assignment into a list of simple assignments: one Variable is assigned one Number or a list of Numbers.
Input consists of a single line — the assignment expression to be executed.
If the assignment cannot be performed output a single number -1. Otherwise, output must contain a simple assignment expression for each variable in lexicographical order one per line. The simple assignment is defined by the following grammar
SimpleAssignment = Variable, " = ", NumberOrList;
NumberOrList= Number | ( "(", NumberOrList, { Comma, NumberOrList }, [ Comma ] ")" ) | EmptyList;
The assignment expression is guaranteed to be grammatically correct.
Length of the input is no more than 104 symbols.
No. | Standard input | Standard output |
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1 |
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2 |
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3 |
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4 |
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