Comments on: Traversing a matrix in spiral order

By: Huy

Huy — Fri, 24 Nov 2017 16:11:18 +0000

does anybody have code on FREE PASCAL???

By: Hem Kumar Newar

Hem Kumar Newar — Sat, 22 Mar 2014 18:08:24 +0000

but this code works only for square matrix. can you give a more generalized code for any matrix size.

By: olivia

olivia — Wed, 21 Aug 2013 13:05:41 +0000

This will not work for cases where row and column sizes are different and specially in cases where rowstart equals rowend and columnstart equals columnend. in those cases there will be duplicacy of the results printed.
working code :
void traverseMatrixSpirally(int ** a, int numOfRows , int numOfCols).
{
int cs = 0;.
int rs = 0;.
int ce = numOfCols-1;.
int re = numOfRows-1;.
int i, j;
while(rs<= re && cs <= ce).
{
for (i = rs, j = cs ; j<= ce; j++).
Console::Write(" " + a[i][j]);.
if(rs==re)
return;
for(j–, i=rs+1;i=cs; j–).
Console::Write(” ” + a[i][j]);.
for(j++, i=re-1;i>=rs+1;i–)
Console::Write(” ” + a[i][j]);.
cs++; rs++; ce–; re–;.
}
}

By: Olivia Biswas

Olivia Biswas — Wed, 21 Aug 2013 13:03:33 +0000

This will not work for cases where row and column sizes are different and specially in cases where rowstart equals rowend and columnstart equals columnend. in those cases there will be duplicacy of the results printed.
working code :
void traverseMatrixSpirally(int ** a, int numOfRows , int numOfCols).
{
int cs = 0;.
int rs = 0;.
int ce = numOfCols-1;.
int re = numOfRows-1;.
int i, j;
while(rs<= re && cs <= ce).
{
for (i = rs, j = cs ; j<= ce; j++).
Console::Write(" " + a[i][j]);.
if(rs==re)
return;
for(j–, i=rs+1;i<=re;i++)
Console::Write(" " + a[i][j]);.
if(cs==ce)
return;
for(i–, j=ce-1; j>=cs; j–).
Console::Write(" " + a[i][j]);.
for(j++, i=re-1;i>=rs+1;i–)
Console::Write(" " + a[i][j]);.
cs++; rs++; ce–; re–;.
}
}

By: Kamal Rawat

Kamal Rawat — Thu, 20 Sep 2012 08:03:01 +0000

In reply to Kuchu.

The main for loop has 4 loops.. the first inner loop will traverse the top row (left to right), second the last column (Top to Down), 3rd will traverse the last row (Right to Left) and final will traverse the first column (Bottom-Up)..
Once the first pass is over (two top/bottom rows and left/right columns are printed).. then the moves on to print the inner matrix.. the start point will be (1,1) hence 2nd row from top will be printed, similarly the 2nd last column will be printed followed by 2nd last row and 2nd column..
And so on..

By: Kuchu

Kuchu — Wed, 19 Sep 2012 17:45:17 +0000

i think this is doing something different. You very first for loop is going down on the left instead of going right at the top. IOW, I don’t think you should be fixing i and incrementing j.

By: Kamal Rawat

Kamal Rawat — Thu, 16 Aug 2012 15:39:02 +0000

In reply to chinky4u. My bad.. messed it up during copy-pasting the code from computer to website.. thanks for pointing it out.

By: chinky4u

chinky4u — Thu, 16 Aug 2012 05:45:38 +0000

can i please see the code?