POJ2976-Dropping tests-最大化平均值

原题链接 Dropping tests Time Limit: 1000MS Memory Limit: 65536K Total Submissions: 11056 Accepted: 3857 Description

In a certain course, you take n tests. If you get ai out of bi questions correct on test i, your cumulative average is defined to be

.

Given your test scores and a positive integer k, determine how high you can make your cumulative average if you are allowed to drop any k of your test scores.

Suppose you take 3 tests with scores of 5/5, 0/1, and 2/6. Without dropping any tests, your cumulative average is . However, if you drop the third test, your cumulative average becomes .

Input

The input test file will contain multiple test cases, each containing exactly three lines. The first line contains two integers, 1 ≤ n ≤ 1000 and 0 ≤ k < n. The second line contains n integers indicating ai for all i. The third line contains n positive integers indicating bi for all i. It is guaranteed that 0 ≤ ai ≤ bi ≤ 1, 000, 000, 000. The end-of-file is marked by a test case with n = k = 0 and should not be PRocessed.

Output

For each test case, write a single line with the highest cumulative average possible after dropping k of the given test scores. The average should be rounded to the nearest integer.

Sample Input

3 1 5 0 2 5 1 6 4 2 1 2 7 9 5 6 7 9 0 0 Sample Output

83 100 Hint

To avoid ambiguities due to rounding errors, the judge tests have been constructed so that all answers are at least 0.001 away from a decision boundary (i.e., you can assume that the average is never 83.4997).

Source

Stanford Local 2005 题意：从n门成绩中取出k门成绩，剩下的成绩算加权平均数（如题），求最大的平均数（四舍五入） 思路：二分平均数，这k门成绩单位均值的计算方式与x满足这样的关系 通过变形可以得到 所以我们只需要按照这个式子进行处理然后排序找到后n-k位加和看是不是大于等于0即可知道该平均数是否符合条件