RosettaCodeData/Task/Fibonacci-sequence/COBOL/fibonacci-sequence-2.cobol

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COBOL

>>SOURCE FREE
IDENTIFICATION DIVISION.
PROGRAM-ID. fibonacci-main.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 num PIC 9(6) COMP.
01 fib-num PIC 9(6) COMP.
PROCEDURE DIVISION.
ACCEPT num
CALL "fibonacci" USING CONTENT num RETURNING fib-num
DISPLAY fib-num
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END PROGRAM fibonacci-main.
IDENTIFICATION DIVISION.
PROGRAM-ID. fibonacci RECURSIVE.
DATA DIVISION.
LOCAL-STORAGE SECTION.
01 1-before PIC 9(6) COMP.
01 2-before PIC 9(6) COMP.
LINKAGE SECTION.
01 num PIC 9(6) COMP.
01 fib-num PIC 9(6) COMP BASED.
PROCEDURE DIVISION USING num RETURNING fib-num.
ALLOCATE fib-num
EVALUATE num
WHEN 0
MOVE 0 TO fib-num
WHEN 1
MOVE 1 TO fib-num
WHEN OTHER
SUBTRACT 1 FROM num
CALL "fibonacci" USING CONTENT num RETURNING 1-before
SUBTRACT 1 FROM num
CALL "fibonacci" USING CONTENT num RETURNING 2-before
ADD 1-before TO 2-before GIVING fib-num
END-EVALUATE
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END PROGRAM fibonacci.