POJ 3632 Optimal Parking

Optimal Parking

Description

When shopping on Long Street, Michael usually parks his car at some random location, and then walks to the stores he needs. Can you help Michael choose a place to park which minimises the distance he needs to walk on his shopping round? Long Street is a straight line, where all positions are integer. You pay for parking in a specific slot, which is an integer position on Long Street. Michael does not want to pay for more than one parking though. He is very strong, and does not mind carrying all the bags around.

Input

The first line of input gives the number of test cases, 1 ≤ t ≤ 100. There are two lines for each test case. The first gives the number of stores Michael wants to visit, 1 ≤ n ≤ 20, and the second gives their ninteger positions on Long Street, 0 ≤ x_i ≤ 99.

Output

Output for each test case a line with the minimal distance Michael must walk given optimal parking.

Sample Input

2424 13 89 3767 30 41 14 39 42

Sample Output

15270

这道题真的是很无奈了，很水的一道题。一分钟就能写完，但是因为是个人训练，看了好几遍都没看懂。

后来过了一道题之后回来看这道题才看懂。这道题的意思就是一条街道，给你其中的几个点，问你把车停在哪里可以保证走遍所有点的情况下走的最短的路，输出走的最短距离。直接找到最小位置和最大位置，相减后*2就行了（去了还要返回的）。

AC代码：

#include<iostream>#include<algorithm>#include<cstring>#include<cstdio>#include<iomanip>using namespace std;int main(){int T,n;int a;cin>>T;int mx,mn;while(T--){cin>>n;cin>>a;mx=mn=a;for(int i=1;i<n;i++){cin>>a;if(mx<a)mx=a;if(mn>a)mn=a;}cout<<2*(mx-mn)<<endl;}return 0;}