#include<iostream>
#include<vector>
using namespace std;
int main()
{
int n, i, Sum(0), sum(0), count(0);
cin >> n;
vector<int>a;
while (cin >> i)
{
Sum += i;
a.push_back(i);
}
for (i = 0; i < n; i++)
a[i] -= Sum / n;
for (i = 0; i <n-1; i++)
{
if (a[i] + sum != 0)
count++;
sum += a[i];
}
cout << count;
}
把N堆纸牌分成左右两部分,来计算两堆纸牌间是否要交换。