HDU 4908 BestCoder Sequence

#include <cstdio>
#include <cstring>
using namespace std;

#define N 40001

int a[N], cnt[N << 1];

int main() {
    int n, m, p;
    while (~scanf("%d%d", &n, &m)) {
        for (int i = 0; i < n; i++) {
            scanf("%d", &a[i]);
            if (a[i] == m) {
                p = i;
            }
        }
        memset(cnt, 0, sizeof(cnt));
        int ans = 0;
        for (int i = p, t = 0; i >= 0; i--) {
            if (a[i] > m) {
                t++;
            }
            else if (a[i] < m) {
                t--;
            }
            cnt[N + t]++;
        }
        for (int i = p, t = 0; i < n; i++) {
            if (a[i] > m) {
                t--;
            }
            else if (a[i] < m) {
                t++;
            }
            ans += cnt[N + t];
        }
        printf("%d\n", ans);
    }
    return 0;
}