Saturday, September 1, 2012

Tower of Hanoi program in Java ?



The towers of hanoi is a popular problem. You have three poles and n disks which fit on the poles. All disks have different size. They are stacked on pole 1 in the orders of their size. The largest disk is on the bottom, the smallest is on the top.

The task is to move all disk from pole 1 to pole 3 under the following restrictions.

Only one disk can be moved

A larger disk can not be placed on a smaller disk.

The recursive algorithm works like the following: move n-1 disk from the starting pole to the pole which is neither start nor target (intermediate), move disk n to the target pole and then move n-1 disk from the intermediate pole to the target pole. The n-1 disks are moved recursively.


public class MinimumWindow {

public static void move(int n, int startPole, int endPole) {
if (n == 0) {
return;
}
int intermediatePole = 6 - startPole - endPole;
move(n - 1, startPole, intermediatePole);
System.out.println("Move " + n + " from " + startPole + " to "
+ endPole);
move(n - 1, intermediatePole, endPole);
}

public static void main(String[] args) {
move(5, 1, 3);
}

}


Below is the output...

Move 1 from 1 to 3
Move 2 from 1 to 2
Move 1 from 3 to 2
Move 3 from 1 to 3
Move 1 from 2 to 1
Move 2 from 2 to 3
Move 1 from 1 to 3

No comments:

Post a Comment