OPTION ARITHMETIC decimal_HIGH
PRINT
PRINT "〇に属するファレー分数列 ："
PRINT "　　（ 既約分数の分子分母が〇までの隣り合う分数 ）"
PRINT
INPUT PROMPT "自然数？　":n
PRINT "〇 ＝ ";n
PRINT
DIM Q(n^2),W1(n^2),W2(n^2)
LET c = 1
FOR i=1 TO n-1
   FOR j=i+1 TO n
      IF i > 1 AND GCD(i,j) > 1 THEN GOTO 10
      LET Q(c) = i/j
      LET W1(c) = i
      LET W2(c) = j
      LET c = c + 1
10    NEXT j
   NEXT i
   CALL sort (Q,W1,W2,c-1)
   PRINT " 0 / 1　＝　0"
   FOR i=1 TO c-1
      PRINT W1(i);"/";W2(i);" ＝ ";Q(i)
   NEXT i
   PRINT " 1 / 1　＝　1"
   PRINT
   PRINT
   PRINT "隣同士の 分母×分子 の差 （上から順に）："
   FOR i=1 TO c-2
      PRINT  W2(i)*W1(i+1) - W1(i)*W2(i+1);" ";
   NEXT i
   PRINT
   PRINT
END

EXTERNAL FUNCTION GCD(s,t)      ! 最大公約数を求める関数
   OPTION ARITHMETIC decimal_HIGH
   DO
      LET m=MOD(s,t)
      IF m=0 THEN EXIT DO
      LET s=t
      LET t=m
   LOOP
   LET gcd=t
END FUNCTION

EXTERNAL SUB sort(a(),b(),c(),m)
   OPTION ARITHMETIC decimal_HIGH
   FOR i=1 TO m-1
      FOR j=i+1 TO m
         IF a(i)>a(j) THEN
            LET t0=a(j) 
            LET a(j)=a(i)
            LET a(i)=t0
            LET t1=b(j) 
            LET b(j)=b(i)
            LET b(i)=t1
            LET t2=c(j) 
            LET c(j)=c(i)
            LET c(i)=t2
         END IF
      NEXT j
   NEXT i
END SUB