【正文】 MOV DX,AXPOP AXSUB AL,30HMOV AH,0ADD DX,AXJMP A1A2: CMP BP,1JNZ A5NEG DX ；若為負(fù)數(shù)，則取負(fù)A5: MOV NUM[SI],DXMOV BP,0ADD SI,2LOOP BEGINMOV DL,0DH ；回車換行MOV AH,2INT 21HMOV DL,0AHINT 21HMOV BX,0 ；對20 個有符號數(shù)按由小到大順序排序MOV CX,19 ；采用冒泡法，排序后依然存放于NUM 數(shù)組L1: MOV DX,CXL2: MOV AX,NUM[BX]CMP AX,NUM[BX+2]JLE CONT1XCHG AX,NUM[BX+2]MOV NUM[BX],AXCONT1: ADD BX,2LOOP L2MOV CX,DXMOV BX,0LOOP L1MOV CX,20 ；將20 個有符號數(shù)（二進(jìn)制）轉(zhuǎn)換為十進(jìn)制數(shù)MOV SI,0 ；再轉(zhuǎn)換為ASCII 碼并輸出屏幕D1: MOV AX,NUM[SI]ADD SI,2TEST AX,1000HJZ D4PUSH AXMOV DL,39。39。MOV AH,2INT 21HPOP AXNEG AXD4: MOV DI,0MOV DX,0MOV BX,10D2: DIV BXADD DL,30HMOV ASC[DI],DLINC DICMP AX,0JZ D3MOV DX,0JMP D2D3: MOV DL,ASC[DI1]MOV AH,2INT 21HDEC DIJNZ D3MOV DL,39。 39。MOV AH,2INT 21HLOOP D1MOV AH,4CH ；返回DOSINT 21HCODE ENDSEND START16. 編寫多字節(jié)有符號數(shù)的加法程序，從鍵盤接收兩個加數(shù)，在屏幕上顯示結(jié)果。答：DATA SEGMENTSTRING1 DB 39。INPUT FIRST NUM(HEX):39。,0DH,0AH,39。$39。STRING2 DB 39。INPUT SECOND NUM(HEX):39。,0DH,0AH,39。$39。STRING3 DB 39。THE RESULT IS(HEX):39。,0DH,0AH,39。$39。NUM1 DW 0,0 ；存放加數(shù)1NUM2 DW 0,0 ；存放加數(shù)2RESULT DB 0,0,0,0 ；存放結(jié)果DATA ENDSCODE SEGMENTASSUME CS:CODE,DS:DATASTART: MOV AX,DATAMOV DS,AXLEA DX,STRING1 ；輸入第一個加數(shù)（4 位十六進(jìn)制數(shù)）MOV AH,9INT 21HMOV SI,2MOV CX,8CONT: PUSH CXCMP CX,4JNZ B1SUB SI,2B1: MOV CL,4SHL NUM1[SI],CLC1: MOV AH,1INT 21HCMP AL,39。039。JB C1CMP AL,39。F39。JA C1CMP AL,39。A39。JB A1SUB AL,7A1: SUB AL,30HMOV AH,0ADD NUM1[SI],AXPOP CXLOOP CONTMOV DL,0DH ；回車換行MOV AH,2INT 21HMOV DL,0AHINT 21HLEA DX,STRING2 ；輸入第二個加數(shù)（4 位十六進(jìn)制數(shù)）MOV AH,9INT 21HMOV SI,2MOV CX,8CONT1: PUSH CXCMP CX,4JNZ B2SUB SI,2B2: MOV CL,4SHL NUM2[SI],CLC2: MOV AH,1INT 21HCMP AL,39。039。JB C2CMP AL,39。F39。JA C2CMP AL,39。A39。JB A2SUB AL,7A2: SUB AL,30HMOV AH,0ADD NUM2[SI],AXPOP CXLOOP CONT1MOV DL,0DH ；回車換行MOV AH,2INT 21HMOV DL,0AHINT 21HLEA SI,NUM1 ；兩數(shù)相加LEA BX,NUM2LEA DI,RESULTMOV CX,4CLCAD: MOV AL,[SI]ADC AL,[BX]MOV [DI],ALINC SIINC BXINC DILOOP ADLEA DX,STRING3 ；顯示結(jié)果（4 位十六進(jìn)制數(shù)）MOV AH,9INT 21HMOV CX,4MOV DI,3TT: PUSH CXMOV DL,RESULT[DI]MOV CL,4SHR DL,CLADD DL,30HCMP DL,3AHJB D1ADD DL,7D1: MOV AH,2INT 21HMOV DL,RESULT[DI]AND DL,0FHADD DL,30HCMP DL,3AHJB D2ADD DL,7D2: MOV AH,2INT 21HDEC DIPOP CXLOOP TTMOV AH,4CH ；返回DOSINT 21HCODE ENDSEND START17. 編寫2 位非壓縮型BCD 碼相乘的程序。答：轉(zhuǎn)化成加法進(jìn)行累加運算。DATA SEGMENTDA1 DB 09H,09HDA2 DB 09H,08HRESULT DB 4 DUP(0)DATA ENDSCODE SEGMENTASSUME CS:CODE,DS:DATASTART: MOV AX,DATAMOV DS,AXMOV AL,DA2+1 ；計算加法次數(shù)MOV BL,10MUL BLMOV BL,DA2MOV BH,0ADD AX,BXMOV CX,AXCONT: MOV AH,0 ；通過循環(huán)做累加MOV AL,RESULTADD AL,DA1AAAMOV RESULT,ALMOV AL,RESULT+1ADD AL,AHMOV AH,0AAAADD AL,DA1+1AAAMOV RESULT+1,ALMOV AL,RESULT+2ADD AL,AHMOV AH,0AAAMOV RESULT+2,ALMOV AL,RESULT+3ADD AL,AHMOV AH,0AAAMOV RESULT+3,ALLOOP CONTMOV AH,4CH ；返回DOSINT 21HCODE ENDSEND START18. 編寫完整的程序求N！，求N 大于6 時的運算結(jié)果，并在屏幕上顯示結(jié)果。答：DATA SEGMENTN DB 8 。求8 的階乘DATA ENDSCODE SEGMENTASSUME CS:CODE,DS:DATASTART: MOV AX,DATAMOV DS,AXMOV AL,NMOV AH,0CALL FACT ；調(diào)用過程求N！，AX=N，BX=N！CALL B2TODEC ；調(diào)用過程將結(jié)果轉(zhuǎn)換為十進(jìn)制，然后屏幕顯示MOV AH,4CHINT 21HFACT PROCCMP AL,0JNZ CHNMOV BX,1RETCHN: PUSH AXDEC ALCALL FACT ；遞歸調(diào)用N！=N*（N1）！POP AXMUL BXMOV BX,AXRETFACT ENDPB2TODEC PROCMOV CX,10000CALL BINMOV CX,1000CALL BINMOV CX,100CALL BINMOV CX,10CALL BINMOV CX,1CALL BINRETB2TODEC ENDPBIN PROCMOV AX,BXMOV DX,0DIV CXMOV BX,DXMOV DL,ALADD DL,30HMOV AH,2INT 21HRETBIN ENDPCODE ENDSEND START19. 在附加段有一個數(shù)組，首地址為BUFF，數(shù)組中第一個字節(jié)存放了數(shù)組的長度。編一個程序在數(shù)組中查找0，找到后把它從數(shù)組中刪去，后續(xù)項向前壓縮，其余部分補0。答：DATA SEGMENTBUFF DB 10, 1,0,2,3,4,0,5,6,7,0 。10 個數(shù)M EQU 0DATA ENDSCODE SEGMENTASSUME CS:CODE, ES:DATA, DS:DATASTART: MOV AX, DATA 。 初始化ES，DSMOV ES, AXMOV DS, AXMOV AL, M 。 關(guān)鍵字M 存入ALMOV DI, OFFSET BUFFMOV CL, [DI] 。 數(shù)組長度存入CXMOV CH, 0INC DI 。指向數(shù)組起始地址CLD 。清方向標(biāo)志L1: REPNE SCASB 。重復(fù)搜索關(guān)鍵字JNZ STOP 。 未找到，轉(zhuǎn)STOP 結(jié)束JCXZ STOP 。 最后一個數(shù)是M，轉(zhuǎn)STOPPUSH DI 。關(guān)鍵字下一單元地址和循PUSH CX 。環(huán)次數(shù)入棧保護DEL: MOV BL, [DI] 。 前移，末尾補0MOV [DI1], BLINC DILOOP DELMOV BYTE PTR[DI1], 0POP CX 。 恢復(fù)CX，DIPOP DIDEC DI 。 由于REPNE SCASB 已自動加1JMP L1STOP: MOV AH, 4CHINT 21HCODE ENDSEND START20. 編程完成將第二個字符串插入到第一個字符串的指定位置上。答：DATA SEGMENTSTRING1 DB 39。THIS IS THE FIRST STRING!39。,39。$39。DB 100 DUP(0) 。緩沖區(qū)NUM1 DW ? ；字符串1 的長度STRING2 DB 39。the second string!39。,39。$39。NUM2 DW ? ；字符串2 的長度POS DW 8 ；插入位置DATA ENDSCODE SEGMENTASSUME CS:CODE,DS:DATA,ES:DATASTART: MOV AX,DATAMOV DS,AXMOV ES,AXLEA DI,STRING1 ；求字符串1 的長度存入NUM1MOV AL,39。$39。MOV NUM1,0CLDD1: SCASBJZ D2INC NUM1JMP D1D2: LEA DI,STRING2 ；求字符串2 的長度存入NUM2MOV AL,39。$39。MOV NUM2,0CLDD3: SCASBJZ D4INC NUM2JMP D3D4: LEA SI,STRING1 ；將字符串1 自插入位置開始的字符向后移動，ADD SI,NUM1 ；空出位置以便插入字符串2MOV DI,SIADD DI,NUM2STDMOV CX,NUM1SUB CX,POSINC CXREP MOVSBLEA SI,STRING2 ；將字符串2 插入到字符串1 指定位置LEA DI,STRING1ADD DI,POSCLDMOV CX,NUM2REP MOVSBLEA DX,STRING1MOV AH,9INT 21HMOV AH,4CHINT 21HCODE ENDSEND START21. 將學(xué)生的班級、姓名、學(xué)號、課程名、成績定義為一個結(jié)構(gòu)，用結(jié)構(gòu)預(yù)置語句，產(chǎn)生5個學(xué)生的成績登記表，編程序?qū)⒊煽冃∮?0 分的學(xué)生姓名、成績顯示出來。答：STUDENT STRUCCLASS DB ? ；班級NAM DB 39。ABCDE$39。 ；姓名NUM DB ? ；學(xué)號COURSE DB 39。ABCD39。 ；課程SCORE DB ? ；成績STUDENT ENDSDATA SEGMENTSTUDENT1 STUDENT 1,39。XIAOA$39。,001,39。MATH39。,70STUDENT2 STUDENT 1,39。XIAOB$39。,002,39。MATH39。,80STUDENT3 STUDENT 1,39。XIAOC$39。,003,39。MATH39。,50STUDENT4 STUDENT 1,39。XIAOD$39。,004,39。MATH39。,90STUDENT5 STUDENT 1,39。XIAOE$39。,005,39。MATH39。,55DATA ENDSCODE SEGMENTASSUME CS:CODE,ds:DATASTART: MOV AX,DATAMOV DS,AXMOV CX,5 ；通過循環(huán)結(jié)構(gòu)進(jìn)行篩選MOV SI,0CONT: MOV AL,[SI] ；取成績CMP AL,60JAE D1LEA DX,[SI] ；小于60 則顯示姓名和成績MOV AH,9INT 21HMOV DL,39。 39。MOV AH,2INT 21HMOV AL,[SI] ；成績轉(zhuǎn)換為ASCII 碼