September Morn Update

Task/Stern-Brocot-sequence/Fortran/stern-brocot-sequence-1.f

@@ -0,0 +1,31 @@
+* STERN-BROCOT SEQUENCE - FORTRAN IV
+      DIMENSION ISB(2400)
+      NN=2400
+      ISB(1)=1
+      ISB(2)=1
+      I=1
+      J=2
+      K=2
+ 1    IF(K.GE.NN) GOTO 2
+        K=K+1
+        ISB(K)=ISB(K-I)+ISB(K-J)
+        K=K+1
+        ISB(K)=ISB(K-J)
+        I=I+1
+        J=J+1
+        GOTO 1
+ 2    N=15
+      WRITE(*,101) N
+  101 FORMAT(1X,'FIRST',I4)
+      WRITE(*,102) (ISB(I),I=1,15)
+  102 FORMAT(15I4)
+      DO 5 J=1,11
+        JJ=J
+        IF(J.EQ.11) JJ=100
+        DO 3 I=1,K
+          IF(ISB(I).EQ.JJ) GOTO 4
+ 3      CONTINUE
+ 4      WRITE(*,103) JJ,I
+  103   FORMAT(1X,'FIRST',I4,' AT ',I4)
+ 5    CONTINUE
+      END

Task/Stern-Brocot-sequence/Fortran/stern-brocot-sequence-2.f

@@ -0,0 +1,22 @@
+ ! Stern-Brocot sequence - Fortran 90
+      parameter (nn=2400)
+      dimension isb(nn)
+      isb(1)=1; isb(2)=1
+      i=1; j=2; k=2
+      do while(k.lt.nn)
+        k=k+1; isb(k)=isb(k-i)+isb(k-j)
+        k=k+1; isb(k)=isb(k-j)
+        i=i+1; j=j+1
+      end do
+      n=15
+      write(*,"(1x,'First',i4)") n
+      write(*,"(15i4)") (isb(i),i=1,15)
+      do j=1,11
+        jj=j
+        if(j==11) jj=100
+        do i=1,k
+          if(isb(i)==jj) exit
+        end do
+        write(*,"(1x,'First',i4,' at ',i4)") jj,i
+      end do
+      end