hdu.1673.Optimal Parking

Optimal Parking

Time Limit: 3000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 2446 Accepted Submission(s): 2045

Problem 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 n integer positions on Long Street, 0 <= xi <= 99.

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

Sample Input
2
4
24 13 89 37
6
7 30 41 14 39 42

Sample Output
152
70
思路：找到要去商店的中位数，将车停在这里。走到数最小的商店，再返回走到数最大的商店，最后在返回停车的地方。所以走过的路程就是最大数减去最小数乘以2。

#include <stdio.h>
#include <stdlib.h>

int main()
{
    int t,n,i;
    int a[100];
    while(scanf("%d",&t)!=EOF)
    {
        while(t--)
        {
            scanf("%d",&n);
            scanf("%d",&a[0]);
            int max,min;
            max=a[0];
            min=a[0];
            for(i=1;i<n;i++)
            {
                scanf("%d",&a[i]);
                if(a[i]>max)//用擂台法找最大数和最小数
                {
                    max=a[i];
                }
                if(a[i]<min)
                {
                    min=a[i];
                }
            }
            int s=0;
            s=(max-min)*2;
            printf("%d\n",s);
        }
    }
    return 0;
}