RosettaCodeData/Task/Zig-zag-matrix/360-Assembly/zig-zag-matrix.360
2023-07-01 13:44:08 -04:00

81 lines
3.1 KiB
Text

* Zig-zag matrix 15/08/2015
ZIGZAGMA CSECT
USING ZIGZAGMA,R12 set base register
LR R12,R15 establish addressability
LA R9,N n : matrix size
LA R6,1 i=1
LA R7,1 j=1
LR R11,R9 n
MR R10,R9 *n
BCTR R11,0 R11=n**2-1
SR R8,R8 k=0
LOOPK CR R8,R11 do k=0 to n**2-1
BH ELOOPK k>limit
LR R1,R6 i
BCTR R1,0 -1
MR R0,R9 *n
LR R2,R7 j
BCTR R2,0 -1
AR R1,R2 (i-1)*n+(j-1)
SLA R1,1 index=((i-1)*n+j-1)*2
STH R8,T(R1) t(i,j)=k
LR R2,R6 i
AR R2,R7 i+j
LA R1,2 2
SRDA R2,32 shift right r1 to r2
DR R2,R1 (i+j)/2
LTR R2,R2 if mod(i+j,2)=0
BNZ ELSEMOD
CR R7,R9 if j<n
BNL ELSE1
LA R7,1(R7) j=j+1
B EIF1
ELSE1 LA R6,2(R6) i=i+2
EIF1 CH R6,=H'1' if i>1
BNH NOT1
BCTR R6,0 i=i-1
NOT1 B NOT2
ELSEMOD CR R6,R9 if i<n
BNL ELSE2
LA R6,1(R6) i=i+1
B EIF2
ELSE2 LA R7,2(R7) j=j+2
EIF2 CH R7,=H'1' if j>1
BNH NOT2
BCTR R7,0 j=j-1
NOT2 LA R8,1(R8) k=k+1
B LOOPK
ELOOPK LA R6,1 end k; i=1
LOOPI CR R6,R9 do i=1 to n
BH ELOOPI i>n
LA R10,0 ibuf=0 buffer index
MVC BUFFER,=CL80' '
LA R7,1 j=1
LOOPJ CR R7,R9 do j=1 to n
BH ELOOPJ j>n
LR R1,R6 i
BCTR R1,0 -1
MR R0,R9 *n
LR R2,R7 j
BCTR R2,0 -1
AR R1,R2 (i-1)*n+(j-1)
SLA R1,1 index=((i-1)*n+j-1)*2
LH R2,T(R1) t(i,j)
LA R3,BUFFER
AR R3,R10
XDECO R2,XDEC edit t(i,j) length=12
MVC 0(4,R3),XDEC+8 move in buffer length=4
LA R10,4(R10) ibuf=ibuf+1
LA R7,1(R7) j=j+1
B LOOPJ
ELOOPJ XPRNT BUFFER,80 end j
LA R6,1(R6) i=i+1
B LOOPI
ELOOPI XR R15,R15 end i; return_code=0
BR R14 return to caller
N EQU 5 matrix size
BUFFER DS CL80
XDEC DS CL12
T DS (N*N)H t(n,n) matrix
YREGS
END ZIGZAGMA