参考答案：

#include<iostream>
using namespace std;
const int N = 1010;
int a[N];
int main()
{
    int n,sum = 0;
    cin >> n;
	for (int i = 0; i < n; ++ i) cin >> a[i];
	
	for (int i = 0; i < n - 1; ++ i)
	{
		for (int j = i + 1; j < n; ++ j)
		{
			if (a[i] > a[j]) ++ sum;
		}
	}
    cout << sum << endl;
    return 0;
}