根号..是square root吗?
For how many positive integers n does √n differ from √10 by less than
如果√n 减掉√10 并且小过1,那么n的正整数有多少个?
PS.是√10 不是√100
请参考以下计算（以√100为题）
-1 < √n - √100 < 1
-1 < √n - 10 < 1
9 < √n < 11
81 < n < 121
120-82+1= 39