Expert: Joseph Moore - 3/5/2010

Question
my prof gave us a prob: input 25 numbers in two dimensional array like this 1 2 3 4 5
         5 4 3 2 1
         7 8 4 5 5
         4 6 3 5 1
then sort both diagonal in ascending and descending form
i have already did the diagonal from top left to bottom right but the diagonal from lower left to top right gives me headache.
this is my syntax in top left to bottom right:
for(x=1;x<=4;x++){
     for(y=x+1;y<=5;y++)
        if (a[x][x]>a[y][y])
           { temp=a[x][x];
             a[x][x]=a[y][y];
             a[y][y]=temp;
           }
     }
please can you help me how you sort diagonally from bottom left to upper right. i cant get the logic how to do it thank you in advance

Answer
Hi.

You've done a good job with the algorithm to sort the diagonal.  Realistically speaking, there is no difference between sorting top-left to bottom-right than sorting bottom-left to top-right.  The only thing you have to change is the index you are referencing.  Instead of going from [0][0] to [4][4] you are going from [4][0] to [0][4].

With that in mind, give this another shot and see what you can come up with.  If you are still having issues, let me know and I'll help you a bit more.