Question

汇编语言编写。 让用户输入一个字符串

RT。之后让用户输入一个字母 。随后输出这个字母在该字符串中出现的次数，然后输出这个字母在字符串中首次出现的位置。

Answer 1

        CODE  SEGMENT
              ASSUME    CS:CODE
              ORG       100H
      START:  JMP       BEGIN
        MSG1  DB        'please input a string: ','$'
        MSG2  DB        'please input a char: ','$'
        LFCR  DB        13,10,'$'
     STRING1  DB        255,?,255 DUP(?)        ; 输入的串长应小于10
       CHAR1  DB        ?
       COUNT  DB        0
         POS  DB        0

      BEGIN:
              PUSH      CS
              POP       DS
              PUSH      CS
              POP       ES
              LEA       DX,MSG1
              MOV       AH,9
              INT       21H
              LEA       DX,STRING1
              MOV       AH,10
              INT       21H
              LEA       DX,LFCR
              MOV       AH,9
              INT       21H
              LEA       DX,MSG2
              INT       21H
              MOV       AH,1
              INT       21H
              MOV       CHAR1,AL
              LEA       DX,LFCR
              MOV       AH,9
              INT       21H
              
              MOV       CL,STRING1+1
              MOV       CH,0
              LEA       SI,STRING1+2
              MOV       BYTE PTR COUNT,0
              MOV       BYTE PTR POS,0
              MOV       BL,0
              CLD
         @0:
              LODSB
              INC       BL
              CMP       AL,CHAR1
              JNE       @2
              INC       BYTE PTR COUNT
              CMP       BYTE PTR COUNT,1
              JNE       @2
              MOV       POS,BL
         @2:
              LOOP      @0
              
              MOV       DL,COUNT
              ADD       DL,30H
              MOV       AH,2
              INT       21H
              MOV       DL,' '
              INT       21H
              MOV       DL,POS
              ADD       DL,30H
              INT       21H
                       
              MOV       AH,4CH
              INT       21H
        CODE  ENDS
              END       START