!
       PROGRAM P103
!
!
!      CLASS LIST UPDATE PROGRAM
!      USING A LINEAR SEARCH BY ID - NOT SORTED
!      ADDITIONS AT END OF FILE
!
!      DECLARE ARRAYS FOR FILE
!
      IMPLICIT NONE
      CHARACTER (LEN=25) :: NAMES(100),NAME
      INTEGER :: ID(100),MARKS(100,7),GRADES(7),I,J
      INTEGER :: NREC,NREQ,KID,NUPD,K
      INTERFACE
      SUBROUTINE SCANID(LIST,N,KEY,KPOS)
      IMPLICIT NONE
      INTEGER ,INTENT(IN OUT) :: LIST(:),KEY
      INTEGER ,INTENT(IN OUT) :: N,KPOS
      END SUBROUTINE SCANID
      END INTERFACE
!
      PRINT *, 'This is Program >> P103 = Update with Linear Search'
!
!     Tell program where data for  READ is coming from
      OPEN(UNIT=5, FILE='P103.DAT')
! UNIT=5 is the default input
!
!
!==== READ IN FILE AND STORE IN MAIN MEMORY
!
L1:   DO J=1,100
         READ 15,ID(J),NAMES(J),(MARKS(J,I),I=1,7)
15       FORMAT(I7,' ',A25,7I3)
         IF(ID(J) == 0) GO TO 101
         Print 15,ID(J),NAMES(J),(MARKS(J,I),I=1,7)
      END DO L1
16    FORMAT(/'TOO MUCH DATA FOR DEFINED ARRAYS'/  &'INCREASE ARRAY SIZE AND RERUN'//)
      STOP
!
!==== READ AND PROCESS UPDATE CARDS
!
101   NREC=J-1
      PRINT 102,NREC
102   FORMAT(/'CLASS LIST UPDATE PROGRAM'/  & I5,' RECORDS ON FILE')
L2:   DO J=1,100
         READ 15,KID,NAME,GRADES
         IF(KID == 0) THEN
            NUPD=J-1
            PRINT 203,NUPD

203         FORMAT(/I5,' UPDATES PROCESSED'/ &/ 'UPDATED CLASS LIST'//)
!
L3:         DO K=1,NREC
               PRINT 211,ID(K),NAMES(K),(MARKS(K,I),I=1,7)
211            FORMAT(I10,'  ',A25,7I5)
!
!===           LEAVE A BLANK LINE EVERY 5
!
               IF(MOD(K,5) == 0) PRINT*  ! Nothing = a blank line
            END DO L3
            STOP

         ELSE
            CALL SCANID(ID,NREC,KID,KPOS)
            IF(KPOS <= 0) THEN
!
!====    GOODIE! WE HAVE A NEW MEMBER OF THE CLASS
!        ADD AT THE END
!
            NREC=NREC+1
            IF(NREC > 100) THEN
               PRINT 220,KID,NAME
220            FORMAT(/'ARRAYS FULL- UNABLE TO ADD',I10,2X,A25)
               STOP
            ENDIF
!
!====       DO ACTUAL UPDATE
!
            ID(NREC)=KID
            NAMES(NREC)=NAME
L4:         DO I=1,7
               MARKS(NREC,I)=GRADES(I)
            END DO L4
            ELSE
!
!==== THIS STUDENT IS ON FILE - UPDATE ANY NONZERO ENTRY IN GRADES
!     INTO THE ARRAY MARKS
!
L5:            DO I=1,7
                  IF(GRADES(I) /= 0) THEN  ! grades(i) not zero
                     MARKS(KPOS,I)=GRADES(I)
                  END IF
               END DO L5
            ENDIF
         ENDIF
      END DO L2
      STOP
      END PROGRAM P103
!
      SUBROUTINE SCANID(LIST,N,KEY,KPOS)
      IMPLICIT NONE
      INTEGER ,INTENT(IN OUT) :: LIST(:),KEY
      INTEGER ,INTENT(IN OUT) :: N,KPOS
      INTEGER :: I
!
!==== LINEAR SEARCH
!
L1:   DO I=1,N
         IF(KEY == LIST(I)) GO TO 100
      END DO L1
      KPOS=0
      RETURN
 100  KPOS=I
      RETURN
      END SUBROUTINE SCANID