Maximise The Score (Codeforces 1930A)
Tags: Greedy, sortings

There are $$$2n$$$ positive integers written on a whiteboard. Being bored, you decided to play a one-player game with the numbers on the whiteboard.You start with a score of $$$0$$$. You will increase your score by performing the following move exactly $$$n$$$ times:   Choose two integers $$$x$$$ and $$$y$$$ that are written on the whiteboard.  Add $$$\min(x,y)$$$ to your score.  Erase $$$x$$$ and $$$y$$$ from the whiteboard.  Note that after performing the move $$$n$$$ times, there will be no more integers written on the whiteboard.Find the maximum final score you can achieve if you optimally perform the $$$n$$$ moves.

Input: Each test contains multiple test cases. The first line contains a single integer $$$t$$$ ($$$1 \leq t \leq 5000$$$) — the number of test cases. The description of the test cases follows.The first line of each test case contains a single integer $$$n$$$ ($$$1 \leq n \leq 50$$$) — the number of integers written on the whiteboard is $$$2n$$$.The second line of each test case contains $$$2n$$$ integers $$$a_1,a_2,\ldots,a_{2n}$$$ ($$$1 \leq a_i \leq 10^7$$$) — the numbers written on the whiteboard.

Output: For each test case, output the maximum final score that you can achieve.

Note: In the first test case, you can only make one move. You select $$$x=2$$$ and $$$y=3$$$, and your score will be $$$\min(x,y)=2$$$.In the second test case, the following is a sequence of moves that achieves a final score of $$$2$$$:  In the first move, select $$$x=1$$$ and $$$y=1$$$. Then, add $$$\min(x,y)=1$$$ to the score. After erasing $$$x$$$ and $$$y$$$, the integers left on the whiteboard are $$$1$$$ and $$$2$$$.  In the second move, select $$$x=1$$$ and $$$y=2$$$. Then, add $$$\min(x,y)=1$$$ to the score. After removing $$$x$$$ and $$$y$$$, no more integers will be left on the whiteboard.  It can be proved that it is not possible to get a score greater than $$$2$$$.In the third test case, you will perform the move thrice, adding $$$1$$$ to the score each time.

Sample Inputs:
3
1
2 3
2
1 1 2 1
3
1 1 1 1 1 1

Sample Outputs:
2
2
3

Solution (Python):
for s in [*open(0)][2::2]:
    print(sum(sorted(map(int, s.split()))[::2]))

Solution (Python):
for s in [*open(0)][2::2]:
    print(sum(sorted(map(int, s.split()))[::2]))

Solution (Python):
for s in [*open(0)][2::2]:
    print(sum(sorted(map(int, s.split()))[::2]))