Box of Bricks
Time Limit: 2 Seconds
Memory Limit: 65536 KB
Little Bob likes playing with his box of bricks. He puts the bricks one upon
another and builds stacks of different height. ``Look, I've built a wall!'',
he tells his older sister Alice. ``Nah, you should make all stacks the same
height. Then you would have a real wall.'', she retorts. After a little con-
sideration, Bob sees that she is right. So he sets out to rearrange the bricks,
one by one, such that all stacks are the same height afterwards. But since Bob
is lazy he wants to do this with the minimum number of bricks moved. Can you
The input consists of several data sets. Each set begins with a line containing
the number n of stacks Bob has built. The next line contains n numbers, the
heights hi of the n stacks. You may assume 1 <= n <= 50 and 1 <= hi
The total number of bricks will be divisible by the number of stacks. Thus,
it is always possible to rearrange the bricks such that all stacks have the
The input is terminated by a set starting with n = 0. This set should not be
For each set, first print the number of the set, as shown in the sample output.
Then print the line ``The minimum number of moves is k.'', where k is the minimum
number of bricks that have to be moved in order to make all the stacks the same
Output a blank line after each set.
5 2 4 1 7 5
The minimum number of moves is 5.
Source: Southwestern Europe 1997