CCCC L2-017. 人以群分 贪心

https://www.patest.cn/contests/gplt/L2-017

题解：贪心，一点小数学

坑：XJB改下标改错了

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <queue>
#include <vector>
#include <cmath>
#include <cstring>
#include <string>
#include <map>
#include<stack>
#include<set>
#include<string.h>
#include<list>
#define pb push_back
#define mp make_pair
#define _for(i, a, b) for (int i = (a); i<(b); ++i)
#define _rep(i, a, b) for (int i = (a); i <= (b); ++i)

using namespace std;
typedef long long ll;
const  int N = 1e5 + 5;
int len;

ll a[N],s[N];
int main() {
    int n;
    cin >> n;
    _for (i, 1, n+1) {
        cin >> a[i]; 
    }
    sort(a+1, a + n+1);
    _for(i, 1, n + 1) {
        s[i] = a[i] + s[i - 1];
    }
    if (n % 2) {
        n++;
        
        printf("Outgoing #: %d
Introverted #: %d
", n / 2, n / 2-1);
        n--;
        cout << "Diff = "<<s[n] - 2 * s[(n-1) / 2];
    
    }
    else {
        printf("Outgoing #: %d
Introverted #: %d
", n / 2, n / 2);
        cout << "Diff = " << s[n] - 2 * s[n / 2]; }
    system("pause");
}
/*1 2 3*/