8 May
2008
8 May
'08
2:21 p.m.
Am Donnerstag, 8. Mai 2008 15:36 schrieb u4538637@anu.edu.au:
Hi I have a bit of a dilemma.I have a list of lists, eg, [[1,2,3],[4,5,6],[7,8,9]]. Imagine they represent a grid with 0-2 on the x axis and 0-2 on the y axis, eg, (0,0) is 1, (1,0) is 2, (2,1) is 6, etc and (2,3) is 9. I want to be able to put in the list of lists, and the (x,y) coordinate, and return the value.
Also, I need to be able to replace a value in the list. Eg, if I wanted to replace (2,3) with 100, then the output of the expression would be [[1,2,3],[4,5,6],[7,8,100]].
Any help would be great!
To get the value at a position, look up (!!) To replace a value, you could use zipWith