第一行一个正整数nn<=1'000'000，表示小朋友的个数．

接下来n行，每行一个整数ai，表示第i个小朋友得到的糖果的颗数．

 //It is made by Awson on 2017.10.23

 #include <set>

 #include <map>

 #include <cmath>

 #include <ctime>

 #include <cmath>

 #include <stack>

 #include <queue>

 #include <vector>

 #include <string>

 #include <cstdio>

 #include <cstdlib>

 #include <cstring>

 #include <iostream>

 #include <algorithm>

 #define LL long long

 #define Min(a, b) ((a) < (b) ? (a) : (b))

 #define Max(a, b) ((a) > (b) ? (a) : (b))

 #define sqr(x) ((x)*(x))

 #define Abs(a) ((a) < 0 ? (-(a)) : (a))

 using namespace std;

 const int N = ;

 LL n, a[N+], m;

 void work() {

   scanf("%lld", &n);

   for (int i = ; i <= n; i++) {

     scanf("%lld", &a[i]); m += a[i];

   }

   m /= n;

   for (int i = ; i <= n; i++) {

     a[i] = a[i-]+a[i]-m;

   }

   sort(a+, a+n+);

   LL mid = a[n>>], ans = ;

   for (int i = ; i <= n; i++) ans += Abs(mid-a[i]);

   printf("%lld\n", ans);

 }

 int main() {

   work();

   return ;

 }