输入一行字符串，统计单词SUN出现的个数

程序运行：

 

代码：

datas segmentENG_max_length     db  0ffhENG_length         db  0ENG                db 100h dup(?)eng_len            dw 0SUN       db 'SUN'sun_len   dw $-SUNcount     dw 0 input     db 'input a line:$'output    db 0DH,0AH,'SUN count:$'
datas endsstacks segment stackdb  100h dup(?)stacks endscodes segmentassume cs:codes,ds:datas,ss:stacks
main   proc  far
start:push dsmov ax,0hpush axmov ax,datas          ;初始化dsmov ds,axlea dx,inputmov ah,9int 21hlea dx,ENG_max_lengthmov ah,10 int 21hmov al,ENG_lengthxor ah,ah mov eng_len,ax	   xor si,sixor di,dimov bp,sun_len           ;取查找单词的长度dec bp                   ;长度减1，指向SUN最后一单元mov cx,eng_len           ;取ENG的长度mov dx,0                 ;记录查找SUN出现的次数s:mov al,ENG[si]cmp SUN[di],al           ;比较SUN[di]与aljnz not_same	             ;若不相等，跳转cmp di,bp                ;判断di是否指向SUN最后一单元jz match                  ;若是，则进行单词左右匹配inc di                    ;若不是，di加1jmp next                  ;跳转至下一次循环match:                      ;单词左右匹配mov di,si                 ;取单词的左边索引sub di,sun_len	          cmp di,0                   ;判断左边索引是否小于0jl  judge_right            ;若小于0,则判断单词右边索引mov bl,ENG[di]                and bl,11011111b           ;将单词左边的字母转成大写cmp byte ptr bl,'A'        ;判断该字母是否小于'A'jb judge_right              ;若小于'A',则判断单词右边索引cmp byte ptr bl,'Z'         ;判断该字母是否大于'Z'ja judge_right              ;若大于'Z',则判断单词右边索引jmp not_same                 ;否则跳转至不匹配judge_right:                   ;单词的右匹配mov di,si                   ;取单词的右匹配索引inc di                       cmp di,eng_len               ;判断右匹配索引是否越界jz same	                     ;若越界，则匹配mov bl,ENG[di]                  ;右匹配的字母转换成大写and bl,11011111b              cmp byte ptr bl,'A'          ;判断该字母是否小于'A'jb  same                      ;若小于'A',则匹配cmp byte ptr bl,'Z'          ;判断该字母是否大于'Z'ja same                       ;若大于'Z',则匹配jmp not_same                  ;否则不匹配same:                        inc dx                        ;匹配，则计算器加1mov di,0                      ;di索引置0jmp next	                      ;跳转置下一次循环not_same:         xor di,di                     ;di置0next:inc si loop smov count,dxlea dx,outputmov ah,9int 21hmov ax,countcall decimalretmain endp
decimal proc near  uses ax bx cx dx mov bx,10 mov cx,0 de:xor dx,dx div bx push dx inc cx cmp ax,0jnz de de1:pop dxadd dl,30hmov ah,2int 21h loop de1retdecimal endp	
codes endsend main