几千几百减几百（不退位）

static void Main(string[] args)
{
while (true)
{
Random r = new Random();
int a, b, c, d,e,f;
a = r.Next(1,10);
b = r.Next(1,10);
c = r.Next(1,b);
d = a * 1000 + b * 100;
e = c * 100;
if (b>=c)
{
f = d - e;
Console.WriteLine(d+"-"+e+"="+f);
}
Console.ReadLine();
}
}

几千几百减几百（不退位）

原文：http://www.cnblogs.com/happinesshappy/p/4379204.html