Problem

听说灌水区大佬多，求解。

40分，WA声一片，下载数据也没用，下来的数据线下测是对的，线上就WA 了

#include <bits/stdc++.h>
using namespace std;
long long int a[30][30], n, m, x, y;

bool check(long long int xx, long long int yy) {
	if (xx == x && yy == y)
		return false;
	if (max(abs(xx - x), abs(yy - y)) == 2 && min(abs(xx - x), abs(yy - y)) == 1)
		return false;
	return true;
}

int main() {
	cin >> n >> m >> x >> y;
	a[x][y] = 0;
	a[0][0] = 1;
	for (long long int i = 0; i <= n; i++) {
		for (long long int j = 0; j <= m; j++) {
			if (check(i, j) && (i != 0 || j != 0))
				a[i][j] = a[i - 1][j] + a[i][j - 1];
		}
	}
	printf("%lld", a[n][m]);
	return 0;
}