RosettaCodeData/Task/Roman-numerals-Encode/ALGOL-W/roman-numerals-encode.alg

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BEGIN
PROCEDURE ROMAN (INTEGER VALUE NUMBER; STRING(15) RESULT CHARACTERS; INTEGER RESULT LENGTH);
COMMENT
Returns the Roman number of an integer between 1 and 3999.
"MMMDCCCLXXXVIII" (15 characters long) is the longest Roman number under 4000;
BEGIN
INTEGER PLACE, POWER;
PROCEDURE APPEND (STRING(1) VALUE C);
BEGIN CHARACTERS(LENGTH|1) := C; LENGTH := LENGTH + 1 END;
PROCEDURE I; APPEND(CASE PLACE OF ("I","X","C","M"));
PROCEDURE V; APPEND(CASE PLACE OF ("V","L","D"));
PROCEDURE X; APPEND(CASE PLACE OF ("X","C","M"));
ASSERT (NUMBER >= 1) AND (NUMBER < 4000);
CHARACTERS := " ";
LENGTH := 0;
POWER := 1000;
PLACE := 4;
WHILE PLACE > 0 DO
BEGIN
CASE NUMBER DIV POWER + 1 OF BEGIN
BEGIN END;
BEGIN I END;
BEGIN I; I END;
BEGIN I; I; I END;
BEGIN I; V END;
BEGIN V END;
BEGIN V; I END;
BEGIN V; I; I END;
BEGIN V; I; I; I END;
BEGIN I; X END
END;
NUMBER := NUMBER REM POWER;
POWER := POWER DIV 10;
PLACE := PLACE - 1
END
END ROMAN;
INTEGER I;
STRING(15) S;
ROMAN(1, S, I); WRITE(S, I);
ROMAN(3999, S, I); WRITE(S, I);
ROMAN(3888, S, I); WRITE(S, I);
ROMAN(2009, S, I); WRITE(S, I);
ROMAN(405, S, I); WRITE(S, I);
END.