C++ :

#include <iostream>
#include <string>
using namespace std;
int nums[100000];
int left_num[200000];
int right_num[200000];
int main(void)
{
	int count = 0;
	int mid = 0;
	int pos = 0;	//中位数的下标
	int res = 0;
	cin >> count >> mid;
	for (int i = 0; i < count; i++)
	{
		int temp;
		cin >> temp;
		if (temp > mid)
			nums[i] = 1;
		else if (temp < mid)
			nums[i] = -1;
		else
		{
			nums[i] = 0;
			pos = i;
		}
	}
	int sum = 0;
	left_num[count] = right_num[count] = 1;
	for (int i = pos - 1; i >= 0; i--) 
	{
		sum += nums[i];
		left_num[count + sum] += 1;
	}
	sum = 0;
	for (int i = pos + 1; i < count; i++)
	{
		sum += nums[i];
		right_num[count + sum] += 1;
	}
	for (int i = - count; i <= count; i++)
	{
		res += left_num[count + i] * right_num[count - i];
	}
	cout << res << endl;
	system("pause");
	return 0;
}