DMOPC '22 Contest 2 P5 - Beautiful Bins
View as PDF bins are lined up in a row, numbered 
 to 
 from left to right. Bin 
 initially contains 
 balls, and it is considered beautiful if it contains 
 balls. In one move, you may pick a bin 
 
 with at least 
 balls, move one ball from bin 
 to any bin on its left, and move another ball from bin 
 to any bin on its right. After some sequence of moves, is it possible to make all of the bins beautiful? To ensure the integrity of your solution, there may be up to 
 test cases.
Constraints
The sum of  over all test cases does not exceed 
.
Input Specification
The first line contains a single integer , the number of test cases. The next 
 lines describe the test cases.
The first line of each test case contains a single integer .
The second line of each test case contains  integers 
.
The third line of each test case contains  integers 
.
Output Specification
For each test case, output a single line containing YES if it is possible to make all of the bins beautiful or NO otherwise.
Sample Input
2
5
2 4 4 2 1
4 3 1 3 2
5
1 1 2 4 2
4 3 4 1 3
Sample Output
YES
NO
Explanation for Sample
For the first test case, one possible solution is as follows:
- Move one ball from bin 
to bin
and another from bin
to bin
. The number of balls in each bin is now
.
 - Move one ball from bin 
to bin
and another from bin
to bin
. The number of balls in each bin is now
.
 - Move one ball from bin 
to bin
and another from bin
to bin
. The number of balls in each bin is now
.
 
For the second test case, it can be proven that it is impossible to make all of the bins beautiful.
Comments