[問題]mips combination(C幾取幾)的程式問題

看板Programming作者shivako (shivako)時間18年前 (2007/11/26 09:46)推噓0(0推 0噓 0→)

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我之前用遞迴的方式去寫不過速度實在是不夠快後來就把腦筋動到乘法除法上面想法是：假設要從X之中取Y個數(ex:從五之中挑三個數) 我就先檢查是否 3*2 -1 < 5 因為不是我就把它換乘從五之中取 (5-3) = 2個數然後用陣列把X 到 X-Y+1的數(這題是5,4)存進去接下來依序把陣列中的X值讀出來看是否可以被Y整除可以就把除過的商存回陣列拿Y-1去重新再進行一次一直做到Y=2也結束之後把陣列中的所有X值全部相乘以下是寫出來的code: .data X: .word, 0 Y: .word, 0 str: .asciiz "please type two integers, and each with the enter key\n" str2: .asciiz " is the combination results.\n" strt: .asciiz "got a problen\n" Calc: .space 64 .text .globl main main: #print string li $v0, 4 la $a0, str syscall #read X Y li $v0, 5 syscall sw $v0, X li $v0, 5 syscall sw $v0, Y #start to calc lw $s0,X #s0 = x lw $s1,Y la $s2,Calc step1: #test if x<y slt $t0,$s0,$s1 bne $t0,$zero,change j step2 step2: #test if y*2-1 is bigger than x or not add $t1,$s1,$s1 addi $t1,$t1,-1 slt $t0,$t1,$s0 beq $t0,$zero,minus add $t2,$s0,$zero #X add $t3,$s1,$zero #Y add $t4,$s2,$zero #arrayadress add $s3,$zero,$zero #arraysize step3: #create an array to store sw $t2,0($t4) addi $t2,$t2,-1 addi $t3,$t3,-1 addi $t4,$t4,4 addi $s3,$s3,1 syscall add $t4,$s2,$zero add $t3,$s1,$zero step4: #start to divide lw $t2,0($t4) rem $t0,$t2,$t3 #calc t0 = t2$t3 beq $t0,$zero,divide addi $t4,$t4,4 j step4 step5: #get ready to calc addi $s3,$zero,1 step6: #calc lw $t2,0($s2) mul $s3,$s3,$t2 addi $s2,$s2,4 addi $s3,$s3,-1 bne $s3,$zero,step6 step7: #output li $v0,1 move $a0,$s3 syscall li $v0,4 la $a0,str2 syscall li $v0,10 syscall change: #X,Y中較大的為從中選擇的 add $t5,$s0,$zero add $s0,$s1,$zero add $s1,$t5,$zero j step2 minus: #如果是C7取4這種換成C7取3 addi $s3,$zero,1 beq $s0,$s1,step7 #if X=Y answer would be 1 sub $t5,$s0,$s1 add $s1,$t5,$zero j step3 divide: #得到商數存回陣列檢查Y=2是否已經做完 addi $t1,$zero,1 div $t0,$t2,$t3 sw $t0,0($t4) addi $t3,$t3,-1 beq $t3,1,step5 add $t4,$s2,$zero j step4 可是連一開始都會有問題可以告訴我是哪裏寫錯嗎感謝 -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 140.112.106.60