谜一般的getchar/scanf

本地用getchar()/scanf读入结果正确，提交到洛谷上10分……改成cin竟然AC了？！所以getchar()/scanf在Windows下和Linux下的用法不一样吗？

#include <cstdio>
#include <iostream>

using namespace std;

bool a[2505][2505];
bool vis1[2505][2505], vis2[2505][2505];
int cnt[2505][2505], s;

inline int count(int x1, int y1, int x2, int y2)
{
    return cnt[x2][y2] - cnt[x1-1][y2] - cnt[x2][y1-1] + cnt[x1-1][y1-1];
}

int main()
{
    int total, x, y;
    int n, m;
    char c;
    scanf("%d%d", &n, &m);
    for (int i = 1; i <= n; ++i)
    for (int j = 1; j <= m; ++j)
    {
        getchar();
        c = getchar();
        if (c == '1') a[i][j] = 1;
        cnt[i][j] = cnt[i-1][j] + cnt[i][j-1] - cnt[i-1][j-1] + a[i][j];
    }
    for (int i = 1; i <= n - s; ++i)
    {
        for (int j = 1; j <= m; ++j)
        {
            if (!a[i][j] || a[i+1][j]) continue;
            total = 1;
            x = i + 1;
            y = j + 1;
            if (!vis1[i][j] && j + s <= m)
            while (a[x][y] && count(i, j, x, y) == total+1)
            {
                ++total;
                vis1[x][y] = 1;
                ++x;
                ++y;    
            }
            s = max(s, total);
            x = i + 1;
            y = j - 1;
            if (!vis2[i][j] && j >= s)
            while (a[x][y] && count(i, y, x, j) == total+1)
            {
                ++total;
                vis2[x][y] = 1;
                ++x;
                --y;    
            }
            s = max(s, total);
        }
    }
    printf("%d\n", s);
    return 0;
}