一开始看讨论区一堆说要把 x 和 y 反着读的，结果反着读我却 WA 了。为啥我正常读没有错？

#include <iostream>
#include <string>

using namespace std;

const int N = 505;

int n, m, x, y;
int num[N][N], sum[N][N];
string s;

int main() {
    cin >> n >> m >> x >> y >> s;
    int len = s.size();
    s = " " + s;
    for (int i = 1; i <= n; i++) 
        for (int j = 1; j <= n; j++) num[i][j] = 1;
    for (int i = 0; i < len; i++) {
        if (s[i] == 'N') y++;
        if (s[i] == 'S') y--;
        if (s[i] == 'W') x--;
        if (s[i] == 'E') x++;
        num[x][y] = 0;
        for (int i = 1; i <= n; i++)
            for (int j = 1; j <= n; j++) 
                sum[i][j] += num[i][j], num[i][j]++;
    }
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= n; j++) 
            cout << sum[j][n - i + 1] << " ";
        cout << endl;
    }
    return 0;
}