scanf("%lld%lld%lld", &n, &m, &k);
	c = getchar();
	for (int i = 1; i <= n; i++)
	{
		for (int j = 1; j <= m;j++){
			//scanf("%c", &a[i][j]);
			cin >> a[i][j];
		}
		//c = getchar();
	}

如上，原来的输入是注释掉的，就过了subtask1，改成cin以后就AC了，之前调了几个小时bug调哭了