<a target="_blank" href="http://poj.org/problem?id=1862">點選打開題目</a>
Stripies
Time Limit: 1000MS
Memory Limit: 30000K
Total Submissions: 12587
Accepted: 5957
Description
Our chemical biologists have invented a new very useful form of life called stripies (in fact, they were first called in Russian - polosatiki, but the scientists had to invent an English name to apply for an international patent). The stripies are transparent
amorphous amebiform creatures that live in flat colonies in a jelly-like nutrient medium. Most of the time the stripies are moving. When two of them collide a new stripie appears instead of them. Long observations made by our scientists enabled them to establish
that the weight of the new stripie isn't equal to the sum of weights of two disappeared stripies that collided; nevertheless, they soon learned that when two stripies of weights m1 and m2 collide the weight of resulting stripie equals to 2*sqrt(m1*m2). Our
chemical biologists are very anxious to know to what limits can decrease the total weight of a given colony of stripies.
You are to write a program that will help them to answer this question. You may assume that 3 or more stipies never collide together.
Input
The first line of the input contains one integer N (1 <= N <= 100) - the number of stripies in a colony. Each of next N lines contains one integer ranging from 1 to 10000 - the weight of the corresponding stripie.
Output
The output must contain one line with the minimal possible total weight of colony with the accuracy of three decimal digits after the point.
Sample Input
Sample Output
題目翻譯：給出一個n，然後給出n個菌落的品質，任意兩個菌落m1、m2相撞，會合并成一個新菌落，并且品質會變成 2*sqrt(m1*m2).
求：如何安排菌落相撞的順序，才能使最後相撞後隻剩一個時的品質最小？
解題思路：每次都安排最大的兩個相撞，直到最後剩下一個。使用優先隊列來解決每次都排序的問題。注意精度問題！