Download More RAM (Codeforces 1629A)
Tags: Greedy, sortings

Did you know you can download more RAM? There is a shop with $$$n$$$ different pieces of software that increase your RAM. The $$$i$$$-th RAM increasing software takes $$$a_i$$$ GB of memory to run (temporarily, once the program is done running, you get the RAM back), and gives you an additional $$$b_i$$$ GB of RAM (permanently). Each software can only be used once. Your PC currently has $$$k$$$ GB of RAM.Note that you can't use a RAM-increasing software if it takes more GB of RAM to use than what you currently have.Since RAM is the most important thing in the world, you wonder, what is the maximum possible amount of RAM achievable?

Input: The first line of the input contains a single integer $$$t$$$ ($$$1 \le t \le 100$$$) — the number of test cases. The description of test cases follows.The first line of each test case contains the integers $$$n$$$ and $$$k$$$ ($$$1 \le n \le 100$$$, $$$1 \le k \le 1000$$$). Then two lines follow, each containing $$$n$$$ integers describing the arrays $$$a$$$ and $$$b$$$ ($$$1 \le a_i, b_i \le 1000$$$).

Output: For each test case, output a single line containing the largest amount of RAM you can achieve.

Note: In the first test case, you only have enough RAM to run the third software initially, but that increases your RAM to $$$20$$$ GB, which allows you to use the first software, increasing your RAM to $$$29$$$ GB. The only software left needs $$$30$$$ GB of RAM, so you have to stop here.In the second test case, you can use the first, second, fourth and fifth software that need only $$$1$$$ GB of RAM per software to run to increase your RAM to $$$5$$$ GB, and then use the last remaining one to increase your RAM to $$$6$$$ GB.In the third test case, all the software need more than $$$1$$$ GB of RAM to run, so the amount of RAM you have stays at $$$1$$$ GB.

Sample Inputs:
4
3 10
20 30 10
9 100 10
5 1
1 1 5 1 1
1 1 1 1 1
5 1
2 2 2 2 2
100 100 100 100 100
5 8
128 64 32 16 8
128 64 32 16 8

Sample Outputs:
29
6
1
256

Solution (Python):
for _ in range(int(input())):
    (n, k) = map(int, input().split())
    a = list(map(int, input().split()))
    b = list(map(int, input().split()))
    l = []
    for i in range(n):
        l.append((a[i], b[i]))
    l.sort(key=lambda x: x[0])
    for i in range(n):
        if k >= l[i][0]:
            k += l[i][1]
        else:
            break
    print(k)

Solution (Python):
R = lambda : map(int, input().split())
(t,) = R()
exec(t * 'n,k=R()\nfor x,y in sorted(zip(R(),R())):k+=(x<=k)*y\nprint(k)\n')

Solution (Python):
l = lambda : map(int, input().split())
for _ in range(int(input())):
    (n, k) = l()
    a = list(l())
    b = list(l())
    ab = list(zip(a, b))
    ab.sort()
    for (a, b) in ab:
        if a <= k:
            k += b
    print(k)