蒟蒻的困惑，为什么本地过了，测试全是WA

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

int main()
{
    int n, ans = 1;
    char a[40010];
    for (n = 0; n >= 0; ++n)
    {
        scanf_s("%c", &a[n]);
        if (a[n] == '\n')break;
    }
    for (int i = n; i < n * n; ++i)
        cin >> a[i];
    cout << n << ' ';
    if (a[0] != '0')
    {
        cout << 0 << ' ';
        for (int i = 1; i < n * n; ++i)
        {
            if (a[i] == a[i - 1])++ans;
            else cout << ans << ' ', ans = 1;
        }
    }
    else
    {
        for (int i = 1; i < n * n; ++i)
        {
            if (a[i] == a[i - 1])++ans;
            else cout << ans << ' ', ans = 1;
        }
    }
    cout << ans << ' ';
    return  0;
}