汇编——三个字符串比较

写的比较累赘。。。

data segment

msg1 DB "Please input first string:",'$'
string1 DB 100,0,100 dup('?')

msg2 DB "Please input second string:",'$'
string2 DB 100,0,100 dup('?') 

msg3 DB "Please input third string:",'$'
string3 DB 100,0,100 dup('?') 

msg4 db 0ah,0dh
result DW '?','$'
Data ends

Stack segment para stack
	db20h dup(0)
Stack ends

code segment
Assume Cs:code,Ss:stack,ds:Data
Start:mov ax,data
	mov ds,ax
	mov es,ax
	;处理第1个字符串 
	lea dx,msg1
	mov ah,09h
	int 21h
	
	lea dx,string1
	mov ah,0ah
	int 21h
	
	xor bx,bx
	
	lea dx,msg4
	mov ah,09h
	int 21h
	;处理第二个字符串 
	lea dx,msg2
	mov ah,09h
	int 21h
	
	lea dx,string2
	mov ah,0ah
	int 21h  
	
	lea dx,msg4
	mov ah,09h
	int 21h
	;处理第三个字符串
	lea dx,msg2
	mov ah,09h
	int 21h
	
	lea dx,string3
	mov ah,0ah
	int 21h     
	
	lea dx,msg4
	mov ah,09h
	int 21h
	;第一个与第二个开始比较  
	mov bl,string1+1
	cmp bl,string2+1
	ja lop1
	jb lop2
	jmp lop3

lop1:mov cl,string2+1
	jmp lop3

lop2:mov cl,string1+1
	jmp lop3

lop3:mov cl,bl
	cld
	lea di,string2+2
	lea si,string1+2
	repz cmpsb
	ja mat1
	jb mat2

mat1: ;1比2大的情况  ，2与3再比较
	;嵌套    
	mov bl,string2+1
    cmp bl,string3+1
	ja lop4
	jb lop5
	jmp lop6

    lop4:mov cl,string3+1
	    jmp lop6

    lop5:mov cl,string2+1
	    jmp lop6

    lop6:mov cl,bl
	    cld
	    lea di,string3+2
	    lea si,string2+2
	    repz cmpsb
	    ja mat4
	    jb mat5
	    ;嵌套第2层  
	    
	    mat4: 
	        ;------1比2大，2比3大,ASCII码排序是1>2>3
	        mov result,'3' 
	        lea dx,result
	        mov ah,09h
	        int 21h  
	        mov result,'2' 
	        lea dx,result
    	    mov ah,09h
    	    int 21h
    	    mov result,'1' 
    	    lea dx,result
    	    mov ah,09h
    	    int 21h
            jmp exit 
            
        mat5:
            ;1比2大,2比3小，1和3还需比较
             ;第一个与第三个开始比较  
        	mov bl,string1+1
        	cmp bl,string3+1
        	ja lop7
        	jb lop8
        	jmp lop9
        
            lop7:mov cl,string3+1
            	jmp lop9
            
            lop8:mov cl,string1+1
            	jmp lop9
            
            lop9:mov cl,bl
            	cld
            	lea di,string3+2
            	lea si,string1+2
            	repz cmpsb
            	;ja mat7
            	jb mat8 
            	;------1比2大，2比3小，1比3大
                ;ASCII码排序是1>3>2 
            ;mat7：
                mov result,'3' 
    	        lea dx,result
    	        mov ah,09h
    	        int 21h  
    	        mov result,'1' 
    	        lea dx,result
        	    mov ah,09h
        	    int 21h
        	    mov result,'2' 
        	    lea dx,result
        	    mov ah,09h
        	    int 21h
                jmp exit
            mat8:
                ;------1比2大，2比3小，1比3小
                ;ASCII码排序是3>1>2
                mov result,'2' 
    	        lea dx,result
    	        mov ah,09h
    	        int 21h  
    	        mov result,'1' 
    	        lea dx,result
        	    mov ah,09h
        	    int 21h
        	    mov result,'3' 
        	    lea dx,result
        	    mov ah,09h
        	    int 21h 
                jmp exit
	    ;嵌套第2层
	 ;嵌套

mat2:   
    ;1比2小的情况。1再与3比较
    mov bl,string1+1
    cmp bl,string3+1
	ja lop10
	jb lop11
	jmp lop12

    lop10:mov cl,string3+1
	    jmp lop12

    lop11:mov cl,string1+1
	    jmp lop12

    lop12:mov cl,bl
	    cld
	    lea di,string3+2
	    lea si,string1+2
	    repz cmpsb
	    ja mat10
	    jb mat11  
	        mat10:
	        ;------1比3大的情况
	        ;ASCII码排序是2>1>3
                mov result,'2' 
    	        lea dx,result
    	        mov ah,09h
    	        int 21h  
    	        mov result,'3' 
    	        lea dx,result
        	    mov ah,09h
        	    int 21h
        	    mov result,'1' 
        	    lea dx,result
        	    mov ah,09h
        	    int 21h
        	    jmp exit  
        	mat11:
    	    ;1比2小，1比3小，2和3再比较
        	    mov bl,string2+1
                cmp bl,string3+1
            	ja lop13
            	jb lop14
            	jmp lop15
            
                lop13:mov cl,string3+1
            	    jmp lop15
            
                lop14:mov cl,string2+1
            	    jmp lop15
            
                lop15:mov cl,bl
            	    cld
            	    lea di,string3+2
            	    lea si,string2+2
            	    repz cmpsb
            	    ja mat13
            	    jb mat14  
            	mat13:
                    ;-----1比2小，1比3小，2比3大
                    ;ASCII码排序是2>3>1
                    mov result,'1' 
        	        lea dx,result
        	        mov ah,09h
        	        int 21h  
        	        mov result,'3' 
        	        lea dx,result
            	    mov ah,09h
            	    int 21h
            	    mov result,'2' 
            	    lea dx,result
            	    mov ah,09h
            	    int 21h   
            	    jmp exit
            	mat14:
            	    ;-----1比2小，1比3小，2比3小
            	    ;ASCII码排序是3>2>1
            	    mov result,'1' 
        	        lea dx,result
        	        mov ah,09h
        	        int 21h  
        	        mov result,'2' 
        	        lea dx,result
            	    mov ah,09h
            	    int 21h
            	    mov result,'3' 
            	    lea dx,result
            	    mov ah,09h
            	    int 21h 
            	    jmp exit 
mat3:mov result,'0'

exit:mov ah,4ch
int 21h
code ends
end start