Square
Given a set of sticks of various lengths, is it possible to join them end-to-end
to form a square?
Input file - square.inp
The first line of input contains N, the number of test cases. Each test
case begins with an integer 4 <= M <= 20, the number of sticks. M
integers follow; each gives the length of a stick - an integer between
1 and 10000.
Output file - square.out
For each case, output a line containing "yes" if is is possible to form
a square; otherwise output "no".
Sample Input
3
4 1 1 1 1
5 10 20 30 40 50
8 1 7 2 6 4 4 3 5
Output for Sample Input
yes
no
yes