; 1. Definition of this program: the maximum name is 20 characters, the maximum student number is 10 characters, and the maximum score is 3 digits.
; 2. When the student information is entered, it will automatically end when the information is sufficient; When the number of digits is not enough, press Enter to end.
; 3. When you enter a name, if you enter it directly, it means that the student information input is over and the information processing is entered.
; The program is compiled and debugged in the integrated environment of MASMPlus 1.2, and runs correctly.
code segment
Suppose CS:Code, DS:Code
; -
; Function: displays the string (Str_Addr) at the specified address.
; Entrance:
; Str_Addr= = String address (required in data segment)
; Usage: output string address
; Usage example: Output PromptStr
Output macro string address
Lea dx, Str _ address
mov ah，9
int 2 1h
EndM
; -
; Function: output a character.
; Entry: dl= character to be displayed
Near Output_Chr proc
Push axe
mov ah，02h
int 2 1h
Bangalore torpedo
Soak in water to soften
Output _Chr endp
; -
; Function: output carriage return and line feed
Output _CTLF approach
Push axe
Push dx
mov ah，02h
mov dl，0dh
int 2 1h
mov dl，0ah
int 2 1h
Popular dx
Bangalore torpedo
Soak in water to soften
Output _CTLF endp
; -
; Function: take the cursor position
; Entrance: None
; Exit: DH= line number, DL= column number.
Near GetCursor Proc
Push axe
Push BX
Push CX
BX XOR BX
MOV, 3
INT 10H
MOV cursor _ line, DH
MOV cursor _Col, DL
Pop CX
Pop bx
Bangalore torpedo
Soak in water to soften
Cursor_Row DB？
Cursor _Col DB?
Get cursor end
; -
; Function: Set cursor position
; Entry: Cursor_Row= row coordinates; Cursor _ column: column coordinates)
SetCursor forward to nearby.
Push CX
Push BX
Push axe
MOV DH，Cursor_Row
MOV DL, cursor _ column
BX XOR BX
MOV, 2
INT 10H
Bangalore torpedo
Pop bx
Pop CX
Soak in water to soften
End of SetCursor
; -
; Function: Enter the decimal number with the specified number of digits on the keyboard, convert it into binary number and save it in the specified storage unit.
; Because the maximum data type is limited to word, the maximum number of digits is 5 and the maximum number of unsigned digits is 65536.
; Convention: Enter directly as the number 0.
; Entry: @@Digits= digits; Di= Save the first address of the input number.
; @@Type_Data= saved data type, B= byte type, W= word type.
; Exit: the converted binary number is stored in the unit indicated by di.
The Input_Digit process is approaching.
CR equ 000DH
If equ 000AH
KBBack equ 0008H
Push dx
Push cx
Push bx
Push di
lea di，@@Save_Tmp
Push di
cld
Mov cl, @ @ digits
XOR ch, ch
Push cx
@@Input: Call GetCursor to get the cursor position.
Mov,1; Accept a character from the keyboard.
int 2 1h
Cmp aluminum and chromium; If you type carriage return, you type fewer than n digits.
Jz @ @ ASC _ Dec turn to the number that has been entered.
cmp al，KBBack
Jz @ @ KB _ Back If it is a blank key, please re-enter.
cmp al，' 0 '
Jb @ @ KBBack If it is less than the number "0", please re-enter.
cmp al，' 9 '
Ja @ @ KBBack If it is less than the number "9", please re-enter.
jmp @@Save_Dig
@@KB_Back: dec Cursor_Col
inc cx
December 2 nd
@@KBBack: Call the cursor position of SetCursor.
Jmp @ @ input
@@Save_Dig: and al, 0fh are converted into binary numbers.
Stosb protection
Loop @ @ Input accepts the next number.
@@ASC_Dec: mov ax，cx
Popular cx
Pops
Child cx, ax; Number of digits actually entered
XOR bp, bp
xor dx，dx
Xor ax, ax
Jcxz @ @ Save _ Ret If you enter directly without entering any numbers, please press enter' 0'.
Dec cx actually reduces the number of digits input by 1, and this string of input digits can be converted into binary digits.
Jcxz @ @ One _ Digit If the number entered is only one digit, directly save the binary number.
mov bx， 10
@@Mul_Ten: lodsb
Bytes expand into words.
Add ax, bp
Multiple bx
Mobile bp, ax
loop @@Mul_Ten
@@One_Digit: lodsb
Bytes expand into words.
Add ax, bp
@@Save_Ret: pop di
cmp @@Type_Data，' B '； Byte type?
Jamaican dollar +5
stosw
jmp $+3
stosb
pop bx
Popular cx
Popular dx
Soak in water to soften
@@Digits db？ ; Decimal number
@ @ Type _ Data db' B saved data type. B= byte type, W= word type.
@@Save_Tmp db 16 dup(？ )
Input _ number EndP
; -
; Function: Convert the binary unsigned number in AX into explicit decimal ASCII code and send it to the display screen for display.
; Entry: AX= binary number
; Exit: displays the converted ASCII code at the current cursor position.
Near Dec_ASCII Proc
Push dx
Push bx
Push di
mov bx， 10
lea di，@@Temp_Save[6]
Mov byte pointer [di],' $'
December 2 nd
@@Divide: xor dx，dx
Branch bx
Or dl, 30h
mov [di]，dl
December 2 nd
Test ax, 0ffffh
Jnz @ @ Divide
Company di
Push di
Popular dx
mov ah，9
int 2 1h
Popdi
pop bx
Popular dx
Soak in water to soften
@@Temp_Save db 7 dup(？ )
Dec_ASCII EndP
; -
; Function: convert the binary unsigned number in AL as decimal into explicit decimal ASCII code,
; And sent to the display screen, regardless of rounding.
; Entries: AH= binary number, BH= divisor, CX= reserved decimal places.
; Exit: displays the converted ASCII code at the current cursor position.
Dec_Frac process approaching
Push axe
mov dl，'.'
Call Output _ Chr to display decimal point.
Bangalore torpedo
mov bl， 10； multiplier
@@Dec_Frac: mov al，ah； The remainder is not 0, and the decimal part is processed.
Mul bl multiplies the remainder by 10 and continues the division.
Div bh is divided by the divisor, and the quotient is taken as one decimal place of the result.
Or aluminum, 30h
mov dl，al
Call Output _ Chr to display a decimal place.
Loop @@Dec_Frac
Soak in water to soften
End of Dec_Frac
; -
Name _ Length equ 20 name length
ID _ Length equ 10； Student number length
Info _ student structure; Types of students' information structure
Name_Student db Name_Length dup(？ ) ; (full name)
ID _ student database ID _ length dup (? ) ; Student number
Score _ student db? ; achievement
Information _ Student End
; -
Prompt_Str db 7，' Name '，Name _ Length-4+2 dup(20h)； Name title string
DB' Student ID', 2 dup (20h); Student ID title string
Db' score', CR, lf; Score title string
Database Name _ Length Duplicate ('-'), 2 Duplicate (20h)
Database ID _ Length Duplicate ('-'), 2 Duplicate (20 hours)
db 5 dup('-')，CR，LF，' $ '
Temp_Cursor dw？ ; Input and display the cursor position of student information.
prompt_Ave db CR，LF，' Average:$ '； Prompt display average score
Buffer_Data db？ ,? ，Name_Length+2 dup(？ ) ; Name and student number input buffer
Press the key db CR, LF, CR, LF,' press any key to exit ... $'
Start: push cs
Popular digital camera
Push cs
Pop es makes the data segment, additional segment and code segment the same segment.
Mov @ @ digits, 3; Decimal number
mov @@Type_Data，' B '； The type of data saved. B= byte type, W= word type.
; -
; Displays the name, student number and grade title, and prompts for student information.
Output prompt _ string
Call GetCursor to get cursor position.
Mov Temp _ cursor, dx; Cursor position for saving input and displaying student information.
; -
; Enter the student's name, student number and grades.
Lea di, Score _ Table name, student number and grade storage address
Input_Name: call GetCursor to get the cursor position.
mov Buffer_Data，Name _ Length+ 1； Maximum number of characters allowed to be entered
Push di
lea di，Buffer_Data[2]
Mov cx, (name length +2)/2
Mov ax, 2020h fill in the blanks
Represents stosw
Popdi
Lea dx, Buffer _ Data nameEnter the buffer address.
Ah, 0ah
int 2 1h
lea si，Buffer_Data[ 1]
Lodsb reads the number of characters actually entered.
Test aluminum, aluminum
JZ @ @ l 1； If you enter a student's name and enter it directly, it is considered that you have entered the student's name, student number, grades, etc. It's over. It's time to count the number of students entering.
Mov cx, name _ length; Number of characters in the name
Rep movsb writes into the student information buffer.
add Cursor_Col，Name _ Length+2； Add the column number, name length and 2, and start to enter the student number.
Call SetCursor cursor cursor position
Push di
lea di，Buffer_Data[2]
Mov cx, (name length +2)/2
Mov ax, 2020h fill in the blanks
Represents stosw
Popdi
Lea dx, Buffer _ Data Student ID Enter the buffer address.
Ah, 0ah
int 2 1h
lea si，Buffer_Data[2]
Mov cx, ID _ Length student numeric characters
Rep movsb writes into the student information buffer.
add Cursor_Col，ID _ Length+2； Add up the number of columns and the length of the student number, add 2, and start to enter the grades.
Call SetCursor cursor cursor position
Call Input _ Digit to enter the score.
Call Output _ CTLF；; Output carriage return and line feed
Jmp input name; Enter the next student information.
; -
; Calculate the number of students enrolled.
@@L 1: mov ax，di
Subaxis, Offset Fraction _ Table; Memory capacity occupied by all student information
Mov bl, type Info _ Students information memory capacity of each student.
div bl
mov cx，ax； CX= number of students enrolled
Test cx, cx
jnz @@L00
Jmp Exit _ Proc If you don't enter any information, end the program directly.
; -
; Establish a linked list of student information
@@L00: Push di; Save link list address
Lea ax, the starting address of the Score _ Table student information.
Push cx
@ @ L2:stosw； Save student information address
Add ax and type Info _ Students' information memory capacity of each student.
Loop @@L2
Popular cx
Popular si; Pop up the linked list address to si.
cmp cx，2
Jb exit _ process; If you only enter the information of 1 student, you don't need to sort and display the results.
; -
; Sort by bubble sorting in descending order of scores.
Push si; Stacking and saving linked list addresses
Push CX; Save the number of students
Dec cx is ready to sort by bubble sorting.
@ @ Sort: Push CX; Number of external loops saved in the stack.
Push si; Stack save array address
@@Compare: push si
Pop di assigns the address of the current array element to the target index register for exchange.
Lodsw reads the current student information address into AX.
mov bx，ax
mov al，[bx。 score _ Student]； Read the current student's grades into AL.
mov bx，[si]； Next adjacent student information address
cmp al，[bx。 score _ Student]； Compare the performance of the current student with that of the next student.
Jae @ @ NextOne, if greater than or equal to, will process the next array element without exchanging data.
mov ax，[di]； If less than, read the current student information linked list node.
xchg ax，[si]； Link exchange list element
mov [di]，ax； Save the node address with a larger value.
@ @ next one:loop @ @ Compare； Process the next array element
Popular si; Array address stack
Out-of-loop stack time of pop cx
Loop @ @ sort; Next comparison
Call output _CTLF
; -
; Displays all student information in descending order of grades.
Output Prompt _ Str to display the title of student information.
Call GetCursor to get cursor position.
Mov Temp _ cursor, dx; Cursor position for saving and displaying student information.
Number of pop cx pop-up students
Popular si; Pop-up list address
Push CX; Save the number of students
xor bx，bx； Total initial value
@ @ List _ Info:push CX； Save the number of students
Call GetCursor to get cursor position.
Lodsw reads into a node of the linked list.
Push si; Stacking and saving linked list addresses
Motion si, ax
Push si; Enter the stack to save the student information address.
Yes, yes. name _ Student]； Name and address
Mov cx, name _ length; Name string length
@ @ Dsip _ Name:lodsb； Read in a character
Cmp al, 0dh return character?
Jz @ @ L3 Yes, the name display is over.
mov dl，al
Call Output _ Chr to display a character.
Loop @ @ Dsip _ Name next character
@@L3: add Cursor_Col，Name _ Length+2； Add 2 to the column number and name length to start displaying the student number.
Call SetCursor cursor cursor position
Popular si; Pop-up student information address
Push si; Enter the stack to save the student information address.
Yes, yes. ID _ Student]； Student number address
Mov cx, ID _ Length name string length
@ @ Dsip _ ID:lodsb； Read in a character
Cmp al, 0dh return character?
Jz @ @ L4 Yes, the display of student number is over.
mov dl，al
Call Output _ Chr to display a character.
Loop @ @ Dsip _ ID next character
@@L4: add Cursor_Col，ID _ Length+2； Add 2 to the length of the column number and student number to start displaying the results.
Call SetCursor cursor cursor position
Popular si; Pop-up student information address
Yes, yes. score _ Student]； result address
Lodsb graded reading
XOR, ah
Plus bx, ax; Cumulative total score
Call Dec _ ASCII to convert the binary unsigned number in AX into an explicit decimal ASCII code, and send it to the display screen for display.
Call output _CTLF
Popular si; Pop-up list address
Number of pop cx pop-up students
Loop @ @ List _ Info Next node (student information)
Call output _CTLF
; -
; Calculate and display the average score
Output prompt _ Ave prompt to display average score.
mov ax，bx
Number of pop bx pop-up students
Div bl bisects the integer part.
Mov bh, ah; Save the rest
XOR, ah
Call Dec _ ASCII to display the average score.
mov ah，BH； remainder
mov bh，bl； divisor
mov cx，2； Reserved decimal places
Call Dec _ Frac to convert the binary unsigned number in AL into decimal explicit decimal ASCII code.
; -
Exit_Proc: output Press _ Key to indicate that the operation is completed, and press any key to end the program.
mov ah， 1
int 2 1h
Mov ah, 4ch ends the program.
int 2 1h
Score _ Form:; Student achievement storage area
End of code
End and start; This is the end of compilation.