Proper divisors: Difference between revisions

=={{header|360 Assembly}}==

{{trans|Rexx}}

This program uses two ASSIST macros (XDECO, XPRNT) to keep the code as short as possible.

<lang 360asm>

* Proper divisors 14/06/2016

PROPDIV CSECT

USING PROPDIV,R13 base register

B 72(R15) skip savearea

DC 17F'0' savearea

STM R14,R12,12(R13) prolog

ST R13,4(R15) "

ST R15,8(R13) "

LR R13,R15 "

LA R10,1 n=1

LOOPN1 C R10,=F'10' do n=1 to 10

BH ELOOPN1

LR R1,R10 n

BAL R14,PDIV pdiv(n)

ST R0,NN nn=pdiv(n)

MVC PG,PGT init buffer

LA R11,PG pgi=0

XDECO R10,XDEC edit n

MVC 0(3,R11),XDEC+9 output n

LA R11,7(R11) pgi=pgi+7

L R1,NN nn

XDECO R1,XDEC edit nn

MVC 0(3,R11),XDEC+9 output nn

LA R11,20(R11) pgi=pgi+20

LA R5,1 i=1

LOOPNI C R5,NN do i=1 to nn

BH ELOOPNI

LR R1,R5 i

SLA R1,2 *4

L R2,TDIV-4(R1) tdiv(i)

XDECO R2,XDEC edit tdiv(i)

MVC 0(3,R11),XDEC+9 output tdiv(i)

LA R11,3(R11) pgi=pgi+3

LA R5,1(R5) i=i+1

B LOOPNI

ELOOPNI XPRNT PG,80 print buffer

LA R10,1(R10) n=n+1

B LOOPN1

ELOOPN1 SR R0,R0 0

ST R0,M m=0

LA R10,1 n=1

LOOPN2 C R10,=F'20000' do n=1 to 20000

BH ELOOPN2

LR R1,R10 n

BAL R14,PDIV nn=pdiv(n)

C R0,M if nn>m

BNH NNNHM

ST R10,II ii=n

ST R0,M m=nn

NNNHM LA R10,1(R10) n=n+1

B LOOPN2

ELOOPN2 MVC PG,PGR init buffer

L R1,II ii

XDECO R1,XDEC edit ii

MVC PG(5),XDEC+7 output ii

L R1,M m

XDECO R1,XDEC edit m

MVC PG+9(4),XDEC+8 output m

XPRNT PG,80 print buffer

L R13,4(0,R13) epilog

LM R14,R12,12(R13) "

XR R15,R15 "

BR R14 exit

*------- pdiv --function(x)----->number of divisors---

PDIV ST R1,X x

C R1,=F'1' if x=1

BNE NOTONE

LA R0,0 return(0)

BR R14

NOTONE LR R4,R1 x

N R4,=X'00000001' mod(x,2)

LA R4,1(R4) +1

ST R4,ODD odd=mod(x,2)+1

LA R8,1 ia=1

LA R0,1 1

ST R0,TDIV tdiv(1)=1

SR R9,R9 ib=0

L R7,ODD odd

LA R7,1(R7) j=odd+1

LOOPJ LR R5,R7 do j=odd+1 by odd

MR R4,R7 j*j

C R5,X while j*j<x

BNL ELOOPJ

L R4,X x

SRDA R4,32 .

DR R4,R7 /j

LTR R4,R4 if mod(x,j)=0

BNZ ITERJ

LA R8,1(R8) ia=ia+1

LR R1,R8 ia

SLA R1,2 *4 (F)

ST R7,TDIV-4(R1) tdiv(ia)=j

LA R9,1(R9) ib=ib+1

L R4,X x

SRDA R4,32 .

DR R4,R7 j

LR R2,R9 ib

SLA R2,2 *4 (F)

ST R5,TDIVB-4(R2) tdivb(ib)=x/j

ITERJ A R7,ODD j=j+odd

B LOOPJ

ELOOPJ LR R5,R7 j

MR R4,R7 j*j

C R5,X if j*j=x

BNE JTJNEX

LA R8,1(R8) ia=ia+1

LR R1,R8 ia

SLA R1,2 *4 (F)

ST R7,TDIV-4(R1) tdiv(ia)=j

JTJNEX LA R1,TDIV(R1) @tdiv(ia+1)

LA R2,TDIVB-4(R2) @tdivb(ib)

LTR R6,R9 do i=ib to 1 by -1

BZ ELOOPI

LOOPI MVC 0(4,R1),0(R2) tdiv(ia)=tdivb(i)

LA R8,1(R8) ia=ia+1

LA R1,4(R1) r1+=4

SH R2,=H'4' r2-=4

BCT R6,LOOPI i=i-1

ELOOPI LR R0,R8 return(ia)

BR R14 return to caller

* ---- ----------------------------------------

TDIV DS 80F

TDIVB DS 40F

M DS F

NN DS F

II DS F

X DS F

ODD DS F

PGT DC CL80'... has .. proper divisors:'

PGR DC CL80'..... has ... proper divisors.'

PG DC CL80' '

XDEC DS CL12

YREGS

END PROPDIV

</lang>

{{out}}

<pre>

1 has 0 proper divisors:

2 has 1 proper divisors: 1

3 has 1 proper divisors: 1

4 has 2 proper divisors: 1 2

5 has 1 proper divisors: 1

6 has 3 proper divisors: 1 2 3

7 has 1 proper divisors: 1

8 has 3 proper divisors: 1 2 4

9 has 2 proper divisors: 1 3

10 has 3 proper divisors: 1 2 5

15120 has 79 proper divisors.

</pre>