SOURCE FREE
IDENTIFICATION DIVISION.
PROGRAM-ID. run-length-encoding.
ENVIRONMENT DIVISION.
CONFIGURATION SECTION.
REPOSITORY.
FUNCTION encode
FUNCTION decode
.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 input-str PIC A(100).
01 encoded PIC X(200).
01 decoded PIC X(200).
PROCEDURE DIVISION.
ACCEPT input-str
MOVE encode(FUNCTION TRIM(input-str)) TO encoded
DISPLAY "Encoded: " FUNCTION TRIM(encoded)
DISPLAY "Decoded: " FUNCTION TRIM(decode(encoded))
.
END PROGRAM run-length-encoding.
IDENTIFICATION DIVISION.
FUNCTION-ID. encode.
DATA DIVISION.
LOCAL-STORAGE SECTION.
01 str-len PIC 9(3) COMP.
01 i PIC 9(3) COMP.
01 current-char PIC A.
01 num-chars PIC 9(3) COMP.
01 num-chars-disp PIC Z(3).
01 encoded-pos PIC 9(3) COMP VALUE 1.
LINKAGE SECTION.
01 str PIC X ANY LENGTH.
01 encoded PIC X(200).
PROCEDURE DIVISION USING str RETURNING encoded.
MOVE FUNCTION LENGTH(str) TO str-len
MOVE str (1:1) TO current-char
MOVE 1 TO num-chars
PERFORM VARYING i FROM 2 BY 1 UNTIL i > str-len
IF str (i:1) <> current-char
CALL "add-num-chars" USING encoded, encoded-pos,
CONTENT current-char, num-chars
MOVE str (i:1) TO current-char
MOVE 1 TO num-chars
ELSE
ADD 1 TO num-chars
END-IF
END-PERFORM
CALL "add-num-chars" USING encoded, encoded-pos, CONTENT current-char,
num-chars
.
END FUNCTION encode.
IDENTIFICATION DIVISION.
PROGRAM-ID. add-num-chars.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 num-chars-disp PIC Z(3).
LINKAGE SECTION.
01 str PIC X(200).
01 current-pos PIC 9(3) COMP.
01 char-to-encode PIC X.
01 num-chars PIC 9(3) COMP.
PROCEDURE DIVISION USING str, current-pos, char-to-encode, num-chars.
MOVE num-chars TO num-chars-disp
MOVE FUNCTION TRIM(num-chars-disp) TO str (current-pos:3)
ADD FUNCTION LENGTH(FUNCTION TRIM(num-chars-disp)) TO current-pos
MOVE char-to-encode TO str (current-pos:1)
ADD 1 TO current-pos
.
END PROGRAM add-num-chars.
IDENTIFICATION DIVISION.
FUNCTION-ID. decode.
DATA DIVISION.
LOCAL-STORAGE SECTION.
01 encoded-pos PIC 9(3) COMP VALUE 1.
01 decoded-pos PIC 9(3) COMP VALUE 1.
01 num-of-char PIC 9(3) COMP VALUE 0.
LINKAGE SECTION.
01 encoded PIC X(200).
01 decoded PIC X(100).
PROCEDURE DIVISION USING encoded RETURNING decoded.
PERFORM VARYING encoded-pos FROM 1 BY 1
UNTIL encoded (encoded-pos:2) = SPACES OR encoded-pos > 200
IF encoded (encoded-pos:1) IS NUMERIC
COMPUTE num-of-char = num-of-char * 10
+ FUNCTION NUMVAL(encoded (encoded-pos:1))
ELSE
PERFORM UNTIL num-of-char = 0
MOVE encoded (encoded-pos:1) TO decoded (decoded-pos:1)
ADD 1 TO decoded-pos
SUBTRACT 1 FROM num-of-char
END-PERFORM
END-IF
END-PERFORM
.
END FUNCTION decode.