codeforces 710B Optimal Point on a Line

You are given n points on a line with their coordinates xi. Find the point x so the sum of distances to the given points is minimal.

Input

The first line contains integer n (1 ≤ n ≤ 3·105) — the number of points on the line.

The second line contains n integers xi ( - 109 ≤ xi ≤ 109) — the coordinates of the given n points.

Output

Print the only integer x — the position of the optimal point on the line. If there are several optimal points print the position of the leftmost one. It is guaranteed that the answer is always the integer.

Example
input
4
1 2 3 4
output
2
分析:水题,可是错了4 遍。。。菜啊。题目告诉我们给定一个数n,接下来给你n个在一条直线上的点的坐标,让你在这些点中找到一个点使得它到其他点的距离和最小。说白了就是找呢个排序后的中间点。。我居然去一个个枚举,不T没天理。。
 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 typedef long long ll;
 4 const ll INF = 3 *1e10 + 9;
 5 const int maxn = 3 * 1e5+7;
 6 ll a[maxn];
 7 ll abbs(ll x)
 8 {
 9     return x >= 0? x: -x;
10 }
11 
12 int main()
13 {
14     ios::sync_with_stdio(false);
15     cin.tie(0);
16     int n;
17     cin >> n;
18     for(int i =1; i<= n; i++)
19     {
20         cin >> a[i];
21     }
22     sort(a+1,a+n+1);
23     if(n&1) cout << a[(n+1)/2] << endl;
24     else cout << a[n/2] << endl;
25     return 0;
26 }
原文地址:https://www.cnblogs.com/PrayG/p/5809997.html